BEIJING, March 16 (Reuters) - China has donated 300 tonnes of rice and flour to Mongolia to help fend off the effects of a bitter winter in the remote southwest of the landlocked country, China's Xinhua news agency said on Tuesday.

The severe winter, or zud, has decimated flocks and isolated herders, especially in western Mongolia. The United Nations estimates 2.7 million livestock have died.

Mongolia's foreign policy tries to balance its giant neighbours, Russia and China, but the severe winter added to a straitened state budget and could leave it more reliant on mining projects that tie its economy to China's.