President Evo Morales has threatened to close the US embassy in Bolivia after his official plane was banned from European airspace.
The warning came as four other South American leaders offered him support at a special summit on Thursday.
His plane was forced to land in Austria on Tuesday after France, Portugal, Italy and Spain apparently barred it from flying through their airspace.
There were unfounded suspicions that US fugitive Edward Snowden was on board.
The Bolivian president blamed Washington for pressurising European countries into refusing him passage.