The three countries have refused to accept the credentials of officials sent to staff the embassies in Riyadh, Kuwait City and Washington DC, according to news wire AFP.
The Riyadh embassy already had suspended services to its approximately 1 million citizens, including refugees, and would is set to close on March 20, Arab News reported.
The closures mean Syrians in those countries will not be able to renew passports or access legal representation from Syria.
Saudi Arabia, Kuwait and the US – as well as other Arab monarchies, especially Qatar – have supported the armed revolt in Syria and called for the overthrow of President Bashar Al Assad.
Saudi Arabia and Qatar are believed to have helped finance separate opposition groups in Syria.
