In the 1987 Presidents Cup, USA were beaten 3-1 by Egypt in Seoul, South Korea.
In the same tournament, USA played CD Español in Masan, Thailand in Cheongju, Hungary in Daejeon and South Korea in Busan, all venues also in South Korea.
More recently, in 2010, USA faced Australia in Roodeport, South Africa as a warm-up game before the World Cup.
This is very similar to the preparation for the 2006 World cup, with the USA having played Poland in Kaiserslautern, Germany.
Go back a little further to 1994 and you will find a match between Romania and USA that was played in the Carlsberg Cup Hong Kong.
The year before, in 1993, USA played in a goalless draw against Hungary in Nagoya, Japan.
1975, in the Copa de Mexico, USA played Costa Rica in Mexico City.
FIFA lists all of these games as "friendlies".