HANNOVER, Germany — President Barack Obama on Monday announced the deployment of up to 250 U.S. military personnel to Syria, mostly special operations forces, to assist local troops trying to dislodge Islamic State extremists. He called the move essential to keeping up momentum against the group.

The deployment will bring the number of personnel to roughly 300, up from about 50 special operations forces currently in Syria.

Obama revealed his decision a week after Defense Secretary Ash Carter announced that more than 200 U.S. troops soon will be headed to Iraq, where local forces are also battling Islamic State militants who control areas of that country. He said none of the new forces heading to Syria would participate in direct combat.

“They’re not going to be leading the fight on the ground, but they will be essential in providing the training and assisting local forces,” Obama said during a speech in Germany that capped a weeklong trip that also took him to Saudi Arabia and Great Britain.

IS was a focus of private talks with his counterparts in all three stops.

Senior U.S. officials have been touting the success of the existing U.S. forces in Syria, including their effectiveness in assisting local forces and generating critical intelligence that helps the U.S.-led coalition against IS target insurgents.

“We want to accelerate that progress,” said Ben Rhodes, Obama’s deputy national security adviser.

Obama said U.S.- European collaboration must extend to the threat posed by IS. As he announced deeper U.S. involvement, he urged Europe to step up, too.

Before returning to Washington, Obama huddled with the leaders of Great Britain, Germany, France and Italy. He said ahead of the meeting that he planned to ask those nations to step up their training and airstrike contributions to the campaign against IS and to provide more economic aid to rebuild parts of Iraq recaptured from IS.