A "small number" of U.S troops are deployed on the ground in Yemen to help fight the al-Qaida affiliate there that was controlling a major port city, a defense official said Friday.

A Pentagon spokesman declined to say how many U.S. troops are there supporting operations led by the Yemeni military and the United Arab Emirates around the port city of Mukalla.

"We have a small number of people who have been providing intelligence support," the spokesman, Navy Capt. Jeff Davis, told reporters Friday.

The U.S. troops deployed about two weeks ago and are at a "fixed location" providing intelligence support as well as "airborne [intelligence, surveillance and reconnaissance], advice and assistance with operational planning, maritime interdiction and security operations, medical support and aerial refueling," Davis said.

Militants with al-Qaida in the Arabian Peninsula seized the port city last year amid the chaos of Yemen's civil war. With looted bank money and oil exports, AQAP transformed Yemen's southern coastline into a wealthy ministate.

"We view this as short term," Davis said of the deployments, noting that AQAP has mostly withdrawn from the city after an attack in late April by about 2,000 Yemeni and Emirati troops.

"This is specifically about routing AQAP from Mukalla, and that has largely occurred," Davis said.

The deployment marks the first time the Pentagon has publicly disclosed deployment of U.S. troops to Yemen in more than a year. In March 2015, the U.S. evacuated about 125 special operations troops amid the expanding civil war between government loyalists backed by a Sunni Arab coalition and Houthi rebels supported by Iran.

Additional U.S. support for the Mukalla operations is provided by the amphibious assault ship Boxer, which is staged off the coast of Yemen with about 4,500 Marines from the 13th Marine Expeditionary Unit. The ship is providing medical support to the Emirate troops, Davis said.

The deployment of U.S. troops to Makalla is one of three operations the U.S. military has been conducting in Yemen.

In a separate operation, the U.S. military is providing support for a Saudi-led coalition that is backing the Yemeni government troops in the civil war against Iranian-backed rebels, specifically offering the Saudis intelligence, airborne fuel tankers and thousands of advanced munitions.

At the same time, U.S. aircraft continue to conduct occasional, unilateral "counterterrorism strikes" against specific AQAP militants who pose a potential threat to the Untied States. Since April 23, U.S. aircraft have launched four strikes on AQAP militants in Yemen, killing 10, Davis said.

AQAP was using the Yemeni port city as a "safe haven to plan future attacks against the United States and its interests," Davis said. "They do remain a significant threat to the region and the United States."

Davis said the mission in Yemen is not an "advise and assist" mission like those underway in Iraq and Syria. Instead it would "fall into the category of intelligence support."

"This is really about the liaison to us for information," Davis said.