The border between **Canada and the United States** is the longest international border in the world, stretching approximately **8,891 kilometers (5,525 miles)**, including the border shared with Alaska. It is a peaceful boundary and includes both land and water segments.  **Chile and Argentina:** * **Length:** Approx. **5,308 kilometres** * This is the third-longest international border in the world and the longest in South America. * It follows the Andes mountain range for most of its length, with several high-altitude border crossings. **China and India:** * **Length:** Approx. **3,488 kilometers**
* It is highly disputed in areas such as Aksai Chin and Arunachal Pradesh, leading to occasional tensions between the two nations. **Kazakhstan and Russian Federation:** * **Length:** Approx. **7,644 kilometers** * This is the second-longest international border in the world. * It is largely flat, passing through vast steppes, and is a vital region for trade and natural resources between the two countries.