Eighteen of the 19 US embassies and consulates that were closed in the Middle East and Africa because of a terrorist threat will reopen on Sunday, the State Department said on Friday. The U.S. Embassy in Sanaa, Yemen, will remain closed. The US Consulate in Lahore, Pakistan, which was closed Thursday because of what officials say was a separate credible threat, also was not scheduled to reopen.

In the statement, State Department spokeswoman Jen Psaki did not cite a reason for the decision to reopen the 18 missions. She cited "ongoing concerns about a threat stream indicating the potential for terrorist attacks emanating from al-Qaida in the Arabian Peninsula," or AQAP, for keeping the embassy in Sanaa closed.

"We will continue to evaluate the threats to Sanaa and Lahore and make subsequent decisions about the reopening of those facilities based on that information," Psaki said.

The 19 outposts were closed to the public beginning last Sunday. Most American employees at the U.S. 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 19 closures.

The State Department issued a travel warning Thursday night regarding Pakistan, saying the presence of several foreign and indigenous terrorist groups posed a potential danger to U.S. citizens throughout the country. At the same time officials ordered nonessential government personnel to leave the U.S. Consulate in Lahore.

In an appearance Tuesday on NBC's "The Tonight Show," Obama said the terror threat was "significant enough that we're taking every precaution."

However, closing embassies and consulates called into question Obama's assertion last spring that al-Qaida's headquarters was "a shadow of its former self" and his administration's characterization of the terror network's leadership as "severely diminished" and "decimated." On Friday, the president noted that he was referring to "core al-Qaida" and that "what I also said was that al-Qaida and other extremists have metastasized into regional groups that can pose significant dangers."

"So it's entirely consistent to say that this tightly organized and relatively centralized al-Qaida that attacked us on 9/11 has been broken apart and is very weak and does not have a lot of operational capacity, and to say we still have these regional organizations like AQAP that can pose a threat, that can drive potentially a truck bomb into an embassy wall and can kill some people," he said.

Shutting down so many U.S. missions also raised the thorny issue of security, a political problem for the administration since the deadly assault last September on the U.S. mission in Benghazi, Libya. The deaths of the American ambassador to Libya and three other Americans brought criticism over the lack of security and whether the administration had been forthright about the perpetrators.

The closings covered embassies and other posts stretching 4,800 miles from Tripoli, Libya, to Port Louis, Mauritius, and were not limited to Muslim or Muslim-majority nations.