The U.S. embassy in Yemen was shuttered Sunday morning in response to "ongoing threats" from al Qeada to attack American targets, according to the embassy.

Embassy officials posted the closing on their Web site this morning, accompanied by a brief message warning staff and other Americans in the region to remain vigilant:

On December 31, the U.S. Embassy sent a warden message to Americans citizens in Yemen to remind them of the continuing threat of terrorist actions and violence against American citizens and interests throughout the world.  The U.S. Embassy reminds U.S. citizens to maintain a high level of vigilance and to practice enhanced security awareness.  

The closing comes just a day after the president publicly tied the attempted bombing of Flight 253 to al Qeada terrorists residing within Yemen's borders.

The White House has long signaled concern that Yemeni officials have not done enough to root out these extremists, and at least one official -- Deputy National Security Adviser John Brennan -- said Sunday that the closure "underscores the threat" those terrorists pose to U.S. interests.

"I spoke with our ambassador in Sana'a, Steve Seche, there earlier this morning and last night, looked at the intelligence that's available as far as the plans for Al Qaida to carry out attacks in Sana'a,...[and decided] that it was the prudent thing to do to shut the embassy," Brennan told ABC's "This Week."

"But we're working very closely with the Yemeni authorities to address the threat that is out there," he added. "But, again, it just demonstrates that Al Qaida is determined to carry out these attacks and more determined to thwart those attacks.

However, at least one lawmaker reacted lukewarmly to news of the embassy's closing this morning. Also appearing on Fox News, Sen. Kit Bond (R-Mo.) expressed concern that a shuttered diplomatic presence could hurt U.S. efforts to learn more about local al Qaeda terror plots.

However, Bond cautioned he had has not yet "seen all of the information," and was unaware what specific intelligence prompted Sunday's closure.