President Barack Obama on Monday announced the deployment to Syria of an additional 250 U.S. special operations forces to assist local troops who are trying to dislodge ISIS extremists from their war-torn country, significantly broadening the American presence there.

Also Monday, Syria and Russia signed agreements worth 850 million euros to restore infrastructure in the Arab nation, Russia's RIA news agency quoted Syrian Prime Minister Wael al-Halaki as saying.

"The Russian side were receptive to the idea of restoring infrastructure, accordingly a number of deals were signed," RIA quoted al-Halaki as saying.

Obama, touting recent gains against ISIS, said the added troops would help "to keep up this momentum" against the group.

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

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 ISIS militants who control areas of that country.

He said the newest insertion of U.S. forces will not be in combat roles.

"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 Hannover, Germany, that capped a week-long trip that also took him to Saudi Arabia and the U.K.

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

Senior U.S. officials have been touting the success of the forces in Syria, including their ability to generate critical intelligence that gives the U.S.-led coalition a better view of happenings on the ground, including efforts to target insurgents.

"We want to accelerate that progress," said Ben Rhodes, Obama's deputy national security adviser.

Syrian alliance forces want more support

An alliance of Syrian armed groups fighting ISIS said on Monday it welcomed U.S. plans to send more troops to Syria, but urged greater support including the provision of guided anti-armour missiles.

The Syria Democratic Forces (SDF) alliance, which includes the powerful Kurdish YPG militia, is the main Syrian partner of the United States and its allies in the battle with ISIS.

A pair of U.S. Air Force B-52 Stratofortress bombers from Barksdale Air Force Base, La., land in Qatar in early April. The U.S. Air Force deployed B-52 bombers to Qatar to join the fight against ISIS in Iraq and Syria, the first time they have been based in the Middle East since the end of the Gulf War in 1991. (Corey Hook/U.S. Air Force/Reuters)

"Any support they offer is positive but we hope there will be greater support," SDF spokesman Talal Silo told Reuters.

'Europe and NATO can still do more'

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

The president said he would use a meeting Monday with the leaders of Great Britain, Germany, France and Italy to ask those nations to step up their contributions to the air campaign against ISIS and to training local forces. He said he would seek more economic aid to rebuild parts of Iraq recaptured from ISIS.

"Europe and NATO can still do more," he said. "We need to do everything in our power to stop them."

Obama discussed his troop decision briefly during a broader speech on U.S.-European relations and the importance to the world of continued European unity. Obama urged Europe's leaders to pay attention to income inequality, which he said creates wedges among populations, and other issues including education for young people and equal pay for equal work for women.

"If we do not solve these problems, we start seeing those who would try to exploit these fears and frustrations and channel them in a destructive way," Obama said. He decried an "us-versus-them" mentality that breeds animosity toward immigrants, Muslims and others.

"This is a defining moment and what happens on this continent has consequences for people around the globe," Obama said. "If a unified, peaceful, liberal, pluralistic, free-market Europe begins to doubt itself, begins to question the progress that's been made over the last several decades, then we can't expect the progress that is just now taking hold in many places around the world will continue."

The president's appeal for Europe to stick together came days after he made a forceful argument while in London against Great Britain exiting the European Union. The possibility of Britain leaving the EU in a June referendum, along with the regional terrorist threat and the Syria refugee crisis, has raised questions about the strength of European unity.

Post-Gadhafi Libya fallout discussed

Libya was also expected to be a topic of discussion at Obama's high-level meeting with German Chancellor Angela Merkel, British Prime Minister David Cameron, French President Francois Hollande and Italian Prime Minister Matteo.

Obama discussed Libya during separate talks with Cameron and Merkel. He recently said failure to plan for the fallout after Libyan leader Moammar Gadhafi was toppled in 2011 was his biggest mistake.

Libya since has descended into chaos and become a base for ISIS. But Obama has said he has no plans to send in ground troops and prefers to support a newly installed unity government in the North African country.

Obama has said he remains opposed to large-scale U.S. military intervention in either Iraq or Syria. But he has incrementally deepened U.S. involvement in both countries, opening him up to charges of mission creep.

Carter last week announced the deployment of an additional 217 U.S. troops to Iraq, bringing the total to just over 4,000 in the first major increase in nearly a year. Eight Apache helicopters were also being sent to Iraq for the first time to help fight IS.

Both moves were cast as helping Iraqi forces as they prepare to retake the key northern city of Mosul.