The U.S. State Department says 18 of the 19 embassies and consulates in the Middle East and Africa that were closed due to a security threat will reopen Sunday.
The U.S. embassy in Yemen's capital, Sanaa, will remained closed.
The 19 posts have been closed since Sunday.
U.S. intelligence late last week intercepted electronic conversations in which the al-Qaida chief in Pakistan, Ayman al-Zawahri, ordered the head of its branch in Yemen to carry out an attack. But the two terrorists did not specify exactly where and when the attacks would take place.
The State Department did not specify why it had decided to resume operations at the missions.
Separately, the U.S. consulate in Lahore, Pakistan, which closed Thursday due to a separate threat, also will remain closed.