Mongolia, a vast country of just three million people, has been under increasing strain.
Its once booming economy has ground almost to a halt and its currency, the tugrik, lost nearly a quarter of its value against the dollar last year, prompting interest rate hikes and austerity measures.
At the end of last year, it had $1.3 billion of total reserves, including gold and IMF Special Drawing Rights, but is estimated to have $1.7 billion in external debt maturing in 2017, excluding a swap line with the People's Bank of China.
Moody's said it would decide whether or not to cut the rating within three months. It has already cut it twice in less than six months.
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