Top 10 Longest International Borders

1. Canada - USA: 8,893 km

Canada is the second-largest country in the world, and the USA is the fourth-largest, sharing the longest border. The border comprises two parts, from north to south, the border of Alaska with Yukon in Canada. Stretching from east to west, crossing 12 US states and 7 Canadian provinces. It is the longest international border in the world.

There are various places like homes, airports situated between USA and Canada. A notable example is the town of Derby Line on the border between the USA and Canada. In some cases, a family might cook in one country but eat in the neighboring one. Derby Line is home to the Haskell Free Library and Opera House. Interestingly, the stage of the theater is in Canada, but the entrance and most seats are in the USA. Therefore, the theater has two addresses, one in the USA and one in Canada.

Due to the vast size and diverse landscapes, the USA experiences almost all types of climates. Mild climates are present in most areas, tropical climates in Hawaii and Southern Florida, polar climates in Alaska, semi-arid climates in the Great Plains west of the 100th meridian, desert climates in the Southwest, Mediterranean climates on the California coast, and arid climates in the Great Basin.

2. Argentina - Chile: 5,300 km

The border between these two South American countries is divided by the majestic Andes mountain range and Tierra del Fuego island in the far south. Argentina, the 8th largest country globally, shares its border with Chile, a nation occupying only a quarter of the neighboring land. A statue of Jesus stands in the Andes, symbolizing peace between the South American nations.

Argentina spans 2,766,891 square kilometers, with 2,736,691 square kilometers of land and 30,200 square kilometers (1.1%) of water. Stretching 3,900 km from north to south and 1,400 km from east to west, Argentina's diverse geography includes the fertile Pampas plains at its center, the primary agricultural region. The resource-rich Patagonia extends from the southern half of the country to Tierra del Fuego. The Grand Chaco near the north and the high Andes mountain region along the western border with Chile define the landscape.

As a long and narrow country along the western slope of the Andes, Chile encompasses various terrains. From north to south, it stretches 4,630 km, yet its widest east-west point is only 430 km. With a total area of 756,950 square kilometers, Chile ranks 38th globally in land size. The northern Atacama Desert is a mineral-rich region. The Central Valley, though small, holds historical significance and serves as the economic and population center of the country.

Russia, the largest country globally, covering 1/9 of the Earth's landmass, shares a border over 20,000 km long with 14 countries. Its longest border is with Kazakhstan, a former Soviet state to the south. Russia is also the 9th largest country by land area.

Kazakhstan, a sovereign nation spanning the northern and central parts of the Asian continent, has an area of 2,724,902 square kilometers, larger than Western Europe. Kazakhstan ranks 9th globally in land area, with a small portion of its territory in the western bank of the Ural River, considered part of Europe.

Russia extends across the northern part of the Asian continent. While Russia occupies much of the Arctic and sub-Arctic regions, with less population, economic activity, and physical diversity per unit area compared to most other regions, the southern part of this area has more diverse landscapes and climates. It consists mostly of vast plains in both Europe and Asia, known as Siberia. These plains are mainly grasslands to the south and forests to the north, with tundra along the northern coastline. Major mountain ranges are mostly along the southern border, such as the Caucasus.

India, the 7th largest country globally, shares its longest border with Bangladesh, a nation only 5% the size of India. This is due to a complex system of enclaves in northern Bangladesh, where a portion of Bangladesh's land is within India's territory.

The intricate overlap is evident in India's Cooch-Behar district, where the Balapara Khagrabari area is surrounded by Bangladesh's territory, and Balapara Khagrabari itself surrounds another piece of Bangladesh's land.

Bangladesh is situated in the low-lying Ganges-Brahmaputra river delta. This delta is formed by the confluence of the Ganges, Brahmaputra, and Meghna rivers at their respective branches. The fertile alluvial soil deposited by these rivers has created one of the world's most fertile deltas.

China is the third-largest country in the world with a border stretching over 22,147 km across 16 nations. Its longest border is with Mongolia, spanning 4,677 km. An interesting fact about these two countries is that there are more Mongolian nationals holding Chinese citizenship than Mongolians in Mongolia.

China boasts the world's largest total land border, covering 22,117 km from the Ap Luc River to the Gulf of Tonkin. It shares borders with 14 other countries, holding the top position globally, including Russia, encompassing most of East Asia, bordering Vietnam, Laos, Myanmar, India, Bhutan, Nepal, Pakistan[j], Afghanistan, Tajikistan, Kyrgyzstan, Kazakhstan, Russia, Mongolia, and North Korea. Additionally, China is in proximity to South Korea, Japan, and the Philippines via the sea.

With an area of 1,564,116 square kilometers, Mongolia ranks as the 19th largest country globally, surpassing Iran by a considerable margin. It is significantly larger than the next-ranked country, Peru. Mongolia's geography is diverse, featuring the Gobi Desert in the south and frigid mountainous regions in the north and west. The majority of Mongolia's territory consists of expansive grasslands.

Surprisingly, Russia's borders with three countries made it to the top 10, and this is the southern border. With Mongolia, the country only shares boundaries with Russia and China, but enough to secure two spots on this list.

Mongolia is a landlocked sovereign country situated at the crossroads of Central, Northern, and East Asia. Its territory roughly corresponds to Outer Mongolia in historical terms, and this term is sometimes still used to refer to the current country. With a border to the south with China and to the north with the Russian Federation. Mongolia covers an area of 1,564,116 square kilometers, ranking as the 18th largest and least densely populated sovereign state globally, with a population of approximately 3.3 million. It is also the second-largest landlocked country in the world, after Kazakhstan.

With a vast area of 17,098,246 square kilometers, Russia is the largest country globally, covering almost 1/9 of the Earth's land area. Russia is also the ninth most populous country in the world with 145.8 million people. The Russian territory extends across the entire northern part of Asia and 40% of Europe, spanning 11 time zones and featuring a diverse range of environments and landscapes. Russia holds the world's largest reserves of minerals and energy, making it one of the energy superpowers.

Both allies of Vietnam in our two resistance wars also share a border of nearly 4,000 km. Although Kazakhstan and Mongolia are in between the borders of both, Russia and China still have a fairly long border in the Northern Asia region. The border between the two countries consists of two parts, one longer in the east and a shorter one in the west.

Like many other international borders, a bilateral agreement exists regarding the methods of border management between China and Russia. The current legal agreement was signed in Beijing in 2006. The agreement requires both parties to clear trees in a strip 15 meters wide along the border. There have been several border conflicts between the two countries in 1929 and 1969. In the 1990s, the two countries agreed to significantly reduce the military forces stationed at the border.

The most common practical way to describe Russia is to describe the mainland and the detached part. The border of the mainland Russia has a coastline over 37,000 km along the Arctic and Pacific Oceans, as well as along inland seas, whether small or large, such as the Baltic Sea, the Black Sea, and the Caspian Sea.

The border between these two countries is a hotspot in South Asia, with disputes in the Kashmir region. For China, this is their third-longest border, and for India, it's the second. This border region often witnesses conflicts and tensions, deteriorating relations between the two nations.

With an area of 9,596,961 square kilometers, China is the fourth-largest country in terms of continental area globally and ranks third or fourth in total area depending on the measurement method. The diverse landscape ranges from grassy plains and the Gobi and Taklamakan deserts in the dry north to tropical rainforests in the wetter south.

India has a coastline of 7,517 km, with 5,423 km along the Indian Peninsula and 2,094 km including the Andaman, Nicobar, and Lakshadweep islands. According to the hydrography chart of the Indian Navy, the country's continental coastline consists of 43% sandy beaches, 11% rocky shores, including cliffs, and 46% mud or marshy shores.

9. Brazil - Bolivia: 3,400 km

Brazil is the 5th largest country globally, occupying the majority of the South American continent. Its longest border is with the neighboring country Bolivia.

Brazil is a vast country with a total area of 8,514,876.599 square kilometers, covering half of the South American continent. It shares borders with Argentina, Bolivia, Colombia, French Guiana, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela. As the 5th largest country in the world, it ranks after Russia, Canada, the United States, and China. The territory spans four different time zones. Brazil also boasts a coastline that stretches 7,367 km along the Atlantic Ocean.

With an area of 1,098,580 square kilometers, Bolivia is the 28th largest country globally, equivalent to Mauritania. Bolivia features diverse ecosystems within its territory. The western highlands are part of the Andes mountain range, including the Bolivian Altiplano. The eastern lowlands encompass vast tropical rainforest areas like the Amazon and Chaco regions.

10. USA - Mexico: 3,141 km

Former US President Donald Trump signed a decision to build a wall along the 10th longest border in the world with Mexico. This border spans various terrains, from densely populated areas to uninhabited deserts.

It is also the most frequently crossed border, with over 350 million people traversing between the two countries in a year. Since 2009, for safety purposes, the USA started constructing border fences, with a length of approximately 930 km. Now, the USA plans to build a tall wall along the border with Mexico. Being the third or fourth largest country globally in total area, before or after China (depending on whether the disputed territories between India and China are considered part of China's territory), the USA ranks third in land area, following Russia and China, but preceding Canada.

Mexico is a country in North America. Most of its territory is part of the North American tectonic plate, while a small part belongs to the Pacific and Cocos tectonic plates, located on the Baja California Peninsula. Geographically, the majority of Mexico's land is in North America, while 12% of the territory on the Tehuantepec Isthmus is in Central America. Politically, Mexico is considered a North American country, along with the USA and Canada.