US Citizen applying for a Chinese Visa in Ulan bator

Diane, it is possible that you can get the entry permit in one day. However, sometimes the embassy does not provide rush services, so I suggest you confirm this with the embassy before doing the application. I heard that it's hard to apply for ten-year entry permit in a third country, but you can still try to do so the embassy. To apply for the ten-year one, the remaining validity of your passport should be longer than one year. Other requirements are the same as that for regular entry permits.