Despite repeated assurances from President Obama and military leaders that the U.S. would not send uniformed military personnel into Libya, four U.S. service members arrived on the ground in Tripoli over the weekend.

According to Pentagon spokesman Capt. John Kirby, the four unidentified troops are there working under the State Department's chief of mission to assist in rebuilding the U.S. Embassy.

Kirby noted the embassy in Tripoli was badly damaged during the conflict between Muammar Qaddafi's forces and the rebels.

Two of the military personnel are explosive-ordnance experts who will be used to disable any explosives traps left in the embassy. The other two are "general security," according to Kirby.

State Department spokeswoman Victoria Nuland assured reporters Monday that the four individuals are not in Libya to fight.

"When the president made his commitment to 'no boots on ground' ... obviously that had to do with entering into the fray between the Qaddafi forces and the Libyan freedom fighters, and that's not what these guys are engaged in," Nuland said.

Kirby also made clear these troops are in no way part of a military operation on the ground. They are armed, however, if for some reason they need to protect themselves.

The troops are only expected to be there for a short while. After the assessment of the embassy is complete, they are expected to leave.

Obama assured Americans in March when the bombing campaign over Libya began that there would be no boots on the ground. From the East Room of the White House on March 18, he said: "The United States is not going to deploy ground troops into Libya."

Several days later at the National Defense University in Washington, D.C., he said: "I said that America's role would be limited, that we would not put ground troops into Libya, that we would focus our unique capabilities on the front end of the operation and that we would transfer responsibility to our allies and partners. Tonight, we are fulfilling that pledge."

Since then, U.S. officials speaking on the condition of anonymity have acknowledged the CIA has had a small number of so-called "spotters" on the ground to assist in the NATO mission. It's also well known that other foreign governments have sent special operations forces to fight on the ground with the rebels.

John Bolton, former U.S. ambassador to the United Nations, told Fox News the fact that four troops are on the ground is "no big deal," considering the embassy had been trashed.

"You need this kind of expertise to make it safe for diplomats to return," Bolton said.

Kirby wouldn't say if there were plans to send more U.S. troops in the future.