WASHINGTON » A small number of U.S. special operations forces will be sent to northern Syria to work with local troops in the fight against Islamic State militants, the White House announced today, marking the first time Americans will be deployed openly on the ground in the country.

President Barack Obama ordered the deployment of fewer than 50 commandos to help coalition forces coordinate with local troops, White House spokesman Josh Earnest said.

Earnest insisted their role should not be described as a "combat mission," saying the troops would train, advise and assist local forces in an intensification of the U.S. effort against the Islamic State group. He acknowledged, however, the forces would be taking risks in a dangerous part of the world, where the U.S. also is conducting airstrikes.

"There’s no denying the serious risk they will be facing," Earnest said, but "they are not in a combat mission."

Officials would not say exactly how many troops would go to Syria, detail their role or say how long they would stay. U.S. troops have been on the ground in Syria before, Earnest said, noting a rescue mission more than a year ago and a more recent raid.

Although the number is small, it marks an escalation of U.S. involvement in the fight against the Islamic State, which controls a large part of northern Syria and has its self-proclaimed capital in the Syrian city of Raqqa. The move comes after weeks of deliberation on how to revive the struggling effort in Syria and the failed training and equipping mission there, and follows a visit to the region last week by Marine Gen. Joseph Dunford, the new chairman of the Joint Chiefs of Staff.

One senior official said that a first group of forces — possibly a couple of dozen — will go relatively soon to assess the situation and determine which groups on the ground the U.S. can best work with, including moderate Kurdish and Arab fighters. More special operations forces would follow once the U.S. better determines what the needs are. The initial forces to move in are likely to come from within the region, and they may be supplemented later with commandos from outside the area.

Defense Secretary Ash Carter hinted at the possible changes earlier this week, saying the U.S. was retooling its strategy in Iraq and Syria and would conduct unilateral ground raids if needed to target Islamic State militants. The U.S. has done special operations raids in Syria, and it participated in a ground operation to rescue hostages last week in northern Iraq that resulted in the first U.S. combat death in that country since 2011.

The addition of special operations forces, however, marks a shift for Obama who has steadfastly said he would not put U.S. boots on the ground in Syria.

In recent weeks, U.S. military officials have been signaling greater acceptance for the idea of such a deployment.

Carter told the Senate Armed Services Committee that the U.S. would do more to support moderate Syrian forces fighting IS.

Last week, Dunford met with his top commanders during a stop in Iraq, and told them to broaden their thinking and map out new ways the U.S.-led coalition can put more pressure on the Islamic State fighters.

The U.S. will also be sending additional aircraft, including F-15 fighters and A-10s, to the Incirlik air base in Turkey, likely repositioning them from other spots in the region.

A senior administration official said the U.S. has made good progress in Iraq and Syria when working with effective partners on the ground who can regain territory lost to IS. So the U.S. is moving away from failed approaches, such as the effort to train Syrian rebels outside the country and send them back into Syria.

The officials were not authorized to discuss the matter publicly so spoke on condition of anonymity.

The Obama administration has been weighing how to better enable moderate Syrian forces to step up the fight against IS, particularly as Russia has entered the conflict with airstrikes.

Salama reported from Baghdad. AP Writer Connie Cass contributed from Washington.