The State Department has evacuated some diplomats in Tripoli due to growing demonstrations against the government.
The Pentagon says it has troops in the region on alert in case they are needed to "evacuate" personnel.
The protests that have spread in Libya over the past week stem largely from the passage of a law that bars from public office officials who served in key roles under the deposed Libyan regime of Moammar Gaddafi. There is no indication so far that the demonstrators are targeting Westerners.
Still, a senior defense official said a Marine quick-response team and a Special Operations unit have been placed on alert to ensure that they can respond if they are needed to evacuate personnel. The nearest U.S. troops are stationed in Spain and Italy.
"The reason we're able to have these forces on alert is work the Defense Department has done to have additional response options in the wake of Benghazi," the official said, speaking on the condition of anonymity to discuss contingency plans.
The State Department said in a statement that it has ordered the departure of a handful of "non-essential" personnel from Tripoli as a result of the "unsettled situation," which includes mass protests outside government facilities.
"We have no indication that the current protests are directed toward Westerners," the statement said. "However, sporadic episodes of civil unrest have occurred throughout the country."
The British Embassy also evacuated some employees, the government said in a statement.
The State Department updated its Libya travel warning Thursday, advising against all but essential travel to Tripoli, Benghazi and other areas.
The unrest worsened after the country's new legislature last weekend overwhelmingly passed the bill barring certain figures from serving in government. It could unseat officials who currently hold important jobs.
It is a situation pregnant with irony and only serves to point up the failures of the administration during the Benghazi attacks. JCS Chairman Dempsey said during his Benghazi testimony that it would have taken "20 hours" for any kind of military response to arrive because the planes in Spain and Italy were not on alert.
Of course, the fact that it was September 11 and no forces were deemed necessary to be on alert status is a massive failure bordering on negligence. And it raises sensible questions about why some demonstrations merited an alert while repeated warnings of danger from militias prior to 9/11 2012 didn't.
Democrats claim there are no unanswered questions about the Benghazi attacks, that adequate explanations have already been given by the military, the state department, and the CIA. What they mean is that delving too deeply into the failures of the administration may raise more questions than anyone has so far been able to answer.