There has been no significant new intelligence about potential terror threats against U.S. interests since startling developments tied to al Qaeda that prompted the closure of American embassies throughout the Middle East and Africa this week, multiple sources tell CNN's Barbara Starr and Elise Labott.
But with the terror alert and embassy closings now stretching into a fifth day, a crucial question is how will the United States know when the threat has passed and facilities can re-open?
One senior U.S. official said there is no new threat stream that gives authorities pause. But on the other hand, "we haven't seen anything that turns us off even more."
Officials added that the United States is trying to determine whether its public disclosure of the threat in general and follow up action has disrupted plots or just delayed them.
"We expected something by now. We would not expect them to throw their hands up, but at what point do you reconsider," one official said.
Ultimately it will be a State Department call as to whether to re-open based on intelligence.
A threatening message among senior al Qaeda operatives that was intercepted was the communication that raised alarm bells, leading to the closing of embassies beginning on Sunday.
The end of the Muslim holy month of Ramadan and concern over several major prison breaks involving militants in the region also contributed to the U.S. response.
One official with access to the latest information said "because of the visibility, the likelihood that an attack has been postponed has increased, we hope."
Officials emphasize that nothing is guaranteed.
They also emphasize that the feeling is they are in a no-win situation: if there is no attack everyone says they overreacted. If there is an attack, they failed to prevent it.
While intelligence has focused on Yemen as a possible target, officials are not ruling out other locations.
White House spokesman Jay Carney insisted on Friday that the current threat "is very real" and was more specific than general administration warnings about groups and individuals "out there in the world who want to do harm to the United States."
"I think there will be an assessment and when there is an assessment that this current threat is not what it was, then we will probably change our posture," Carney said. "But I certainly don't have a time line to predict to you."
CNN's Adam Levine contributed to this report.