It borders Russia and People's Republic of China.
The only country which borders both Russia and India is China.
Russia.
China is the only country that borders both Russia and India.
North Korea is bordered by China and Russia to the north.
Amur River
That is Mongolia.
Zero miles. Siberia is a region of Russia which borders China, Mongolia and Kazakhstan.
Yes, Russia borders China to the south-east. It also borders China along a narrow strip west of Mongolia and east of Kazakhstan.
Mongolia, of course!
Russia.
The landlocked country that borders China to the south and Russia to the north is Mongolia. The capital of Mongolia is Ulan Bator.