The new force of 250 American troops who've been ordered that will soon deploy to Syria will operate be near the front lines of the Islamic State-held territory, helping U.S. leaders decide make critical decisions about which local rebel groups should receive vital U.S military support, officials said.

Pentagon officials say these personnel additional U.S. troops will help manage the "transactional" relationship between Washington and the little-known local militias. RLocal rebel commanders who demonstrate show progress against ISIS in fighting the Islamic State will be rewarded with U.S. airstrikes, weapons, ammunition and money.

"Those forces that perform well will get additional U.S. support," said Peter Cook, a Defense Department spokesman, "and these particular U.S. forces will be in the business of trying to identify who those people are," said Peter Cook, a Defense Department spokesman."

President Obama announced the new deployment on Monday during a visit to Germany, saying the additional troops forces would help to keep up "momentum" in the coalition campaign against Islamic State extremists, also known as ISIS or ISIL.

The U.S forces will include special operations teams as well as logistics and medical personnel, Cook said.

"They'll be engaging with forces on the ground, getting a better picture of the battle space, improving our intelligence assessment and our targeting assessment as well," Cook said.

The deployment Deploying 250 more Americans to Syria will marks a significant addition to the first cadre of 50 special operations troops who arrived in Syria deployed in November. It will bring That will bringing the total number of American personnel there at boots on the ground in Syria to about 300.

"The original 50 are providing very, very helpful information," Cook told reporters Monday. "Those [initial] forces have improved our picture of the battlefield, made connections with local, capable forces and enhanced our targeting efforts in Syria. These new forces will expand those efforts and build on what has been working."

The U.S. military's new plan to defeat ISIS

The Obama administration's new plan to defeat the Islamic State group relies on a patchwork of local ground forces moving in large formations to isolate and ultimately invade Mosul in Iraq and Raqqa in Syria.

Since the first 50 American troops deployed to Syria last year, the American-backed rebel alliance has grown significantly and pushed the Islamic State out of several key towns. The long-term U.S. strategy is to limit the militants' ISIS's access to the group's its self-proclaimed capital, Raqqah. The latest fighting has targeted al Shaddadi, a key town along a primary transit route linking ISIS’s two major cities, Raqqah and Mosul.

U.S. forces have reportedly set up a base camp at Rmeilan Air Base in the Syrian Kurdish region, providing a key supply line for U.S. operations in Syria, according to local reports.

The U.S. government considers many of the rebel groups in Syria to be extremists and not reliable partners for fighting the Islamic State. In some cases, American weapons ended up in the hands of groups linked to al Qaida or ISIS. Last year a train-and-equip effort was halted because very few Syrians could pass the strict vetting process.

Cook acknowledged the risks that American troops in Syria will face, but insisted nevertheless said this is not demonstrative of a combat mission, a term that President Obama and many Pentagon officials deliberately avoid.

"They’re in harm's way, that — we should be crystal clear about that. And they will be able to defend themselves if they come under fire. But that is not the intent of this deployment," Cook said.

"The idea is that they will not be engaged in direct combat, they will not be on the front lines. They will be providing support to those local forces that are taking the fight to ISIL," Cook said, referencing another acronym for the group.

Already, the president's critics in Congress have signaled their dissatisfaction with the plan, namely the small U.S. footprint in Syria compared to Iraq, where the American military presence has swelled to more than 4,000 troops.

Among the risks facing American troops is Syria are those troops may face is the daily airstrikes that the Russian military continues to mount from its air base in western Syria. To help protect the initial force of 50 American troops sent in last year, the U.S. used back channel communications to tell the Russians roughly where those American forces were located, an effort to avoid an incident could inflame tensions between Washington and Moscow.

On Monday Cook declined to say whether the U.S. will notify the Russians about the location of these additional forces.

"In the past we have identified, and we did identify a particular geographic area where we asked the Russians not to strike, and I am not going to discuss those conversations going forward, but we're going to take additional steps," Cook said.

"You can be sure to take every step we can to preserve the safety of our personnel and limit the risk they face. But I'm not going to speak to particular conversations, you know, we will have in the future or have had with the Russians at this point."