The US State Department says 18 of the 19 US embassies and consulates in the Middle East and Africa that have been closed due to a terrorist threat will reopen on Sunday or on Monday.
But officials say the US Embassy in Sanaa, Yemen, will remain closed.
A statement did not give a reason for resuming regular business operations at the 18 diplomatic missions.
The 19 outposts had been closed since Sunday. Most American employees at the US Embassy in Yemen were ordered to leave the country on Tuesday because of threat information.
An intercepted message between al Qaida officials about plans for a major terror attack triggered the closures.
A separate threat led to the closure on Thursday of the US Consulate in Lahore, Pakistan. It remains closed.