The US defense officials claimed that 400 Americans will train militant groups fighting against the ISIS in Syria.
The trainers who are in Turkey and Jordan now can set to work this week.
The US officials marked that trained foreign-backed militants would be able to decide to fight the government of Syrian President as well.
The United States will also provide the militants with weapons, trucks and tactical radios for their communication.
The ISIS terrorists, who were initially trained by the CIA in Jordan in 2012 to destabilize the Syrian government, now control large parts of Syria and Iraq.
A string of advances by terrorist groups took place in the northwestern Idlib Province, where the city of Jisr al-Shughur recently fell into the hands of the militants.
Qatar, Saudi Arabia, and Turkey are also supporting the militants operating inside the country.
"We are not talking about tens or hundreds but thousands of battles and... it is the nature of battles for there to be advances and retreats, victories and losses, ups and downs," Bashar al-Assad said, urging the Syrian people to be more vigilant against "the spread of a spirit of frustration or despair at a loss here or there."
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