The region area or country borders china on the east is East China Sea and South China Sea.
The southwest region of the United States borders Mexico.
The landlocked country that borders China to the south and Russia to the north is Mongolia. The capital of Mongolia is Ulan Bator.
It depends on what country is being referred to. Mexico borders the United States on the south. The United States borders Canada to the south. China borders Mongolia on the south.
Afghanistan
Mongolia?
Ulaanbaatar, Mongolia
Google a map. South Korea borders NORTH Korea.
Australia
North Korea, obviously. South Korea hasmaritime borders with China and Japan.
The only nation bordering China, Russia, and South Korea is North Korea.
The country is Mongolia and its capital is Ulan Bator.