A "small number" of U.S. forces have been on the ground in Yemen for the past two weeks helping Yemeni and Emirati forces, led by Saudi Arabia and the United Arab Emirates, battle Al Qaeda in the Arabian Peninsula fighters, the Pentagon announced Friday.

Their presence marks the first time U.S. troops have been on the ground in Yemen since March 2015, when the U.S. military pulled the last of its special operations forces as a civil war raged.

Capt. Jeff Davis, a Pentagon spokesman, said the U.S. forces are providing "intelligence" support to Arab allies fighting AQAP for a "short term."

He declined to offer a more specific timeline or provide the size of the detachment of U.S. forces, characterizing the group as a “small number.”

Davis said there have been four airstrikes against AQAP since late last month. In March, the U.S. military conducted an airstrike in Yemen against the affiliate, killing 70 fighters. The military used jet fighters and drones in the operation, according to officials.

Davis said the U.S. Navy also has positioned the amphibious assault ship USS Boxer and two escort ships, USS Gravely and USS Gonzales, both guided-missile destroyers, off the coast of Yemen. The 13th Marine Expeditionary Unit is headquartered aboard the USS Boxer and has over 2,000 U.S. Marines under its command ready to go ashore if needed.

Two weeks ago, Yemeni and Emirati forces pushed AQAP militants out of the port city of Mukalla, about halfway down Yemen's coastline in the Gulf of Aden.

The civil war in Yemen has drawn support from Middle Eastern countries along sectarian lines since fighting broke out last year.

Iran-backed Houthi rebels have been fighting Yemeni troops loyal to President Abd Rabbuh Mansur Hadi. AQAP has taken advantage of the chaos to expand its control over large portions of the country.

The State Department closed its embassy in Yemen in February 2015. U.S. Marines protecting the embassy were forced to destroy their weapons before boarding a private charter from Oman during the evacuation.