WASHINGTON — The U.S. has added dozens of Marines to the security details at embassies in Jordan, Israel and Turkey because of concerns about unrest linked to the opening of the U.S. embassy in Jerusalem, according to five U.S. defense officials.

The officials say the State Department and the Pentagon are also considering more U.S. military security at embassies in a half dozen other countries in the Middle East with histories of large-scale demonstrations, like Lebanon, Egypt and Pakistan.

Marines are already on the ground and providing additional security to the embassies in Jordan, Israel and Turkey.

The increase at each location is modest — not dozens at any single embassy but not single digits, according to three of the officials.

The State Department issued a new security message for Turkey on May 11, but has not issued any new travel advisories or security messages for Israel or Jordan. A State Department spokesperson did not immediately respond to a request for comment.

There is no timeline for how long the additional security forces will be in the region but one U.S. defense official said they will be there "until security conditions on the ground improve."

Dozens of protestors have died in demonstrations in Gaza in the lead-up to the official and controversial opening of the U.S. embassy in Jerusalem Monday. The U.S. relocated its embassy from Tel Aviv. It is now the only country with its main embassy rather than a consulate in Jerusalem.

The request for additional Marines was made last week by the State Department's Diplomatic Security Service requested. The Marines were supplied by the Marine Security Guard Augmentation Unit (MSAU) in Quantico, Virginia, which has about 135 Marine security guards who can be detailed to increase protection for embassies in the Middle East and around the world.

In a statement, Marine Corps spokesperson Capt. Ryan E. Alvis said, "A number of Marines from the Marine Security Guard Security Augmentation Unit (MSAU) have been requested to augment a number of embassies in light of current events. The exact locations and/or number of Marines will not be released. These Marines, assigned to the Marine Corps Embassy Security Group, headquartered at Quantico, Va., are uniquely postured to respond expeditiously to augment embassies at the request of the State Department. All Marines who comprise the MSAU have served as Marine Corps Security Guards in the past and receive specialized training. While augmenting embassy security, Marines will serve under the authority of the embassy's ambassador or chief of mission."

Should a situation require yet more forces, the Marine Corps also has anti-terrorism FAST companies in the region and an expeditionary unit, the 26th MEU, aboard the amphibious assault ship USS Iwo Jima.