The U.S. Department of State has elevated their travel advisory to level three (reconsider travel). The current CDC travel advisory level is one (practice usual precautions).

This force protection advisory is issued to sensitize DoD personnel
who may be in or traveling to Mongolia on leave or TDY of risks associated
with COVID-19. Subsequent effects of COVID-19 can be limited commercial
travel options should there be an emergency making it difficult to leave if necessary and limited medical capabilities if required. Personnel at all levels should continue to review their FHP posture, raise their awareness and emphasize personal protection.