The US military has started training Syrian fighters to combat Islamic State militants, US and Middle East sources told Reuters on Thursday, speaking on condition of anonymity, adding the program had begun in Jordan and would soon launch in Turkey.
The U.S. plan to train and arm a force that is expected to eventually total more than 15,000 troops is a major test of President Barack Obama's strategy in Syria, which critics say is too limited to steer events.
The Pentagon declined comment. No further details were available, including on the number of forces being trained.
The program itself must overcome deep scepticism, including among rebels fighting inside Syria. Some rebel leaders say the force risks sowing divisions and cannot succeed without directly targeting Syrian government forces.
The Obama administration says the program aims only to target Islamic State forces, since the United States is not at a war with Syria.
But critics, including in the US Congress, say that theoretical limitation is unlikely to withstand the realities of Syria's messy civil war.
US-trained Syrian fighters, they say, are likely to come in contact with Syrian President Bashar al-Assad's forces eventually. And the priority of key US allies in the region, including Saudi Arabia and Turkey, is to topple Assad.
It was unclear whether Obama had yet decided how extensively and under what circumstances Washington might back the force militarily inside Syria – a commitment that would risk the very entanglement in the war that Obama has long sought to avoid.
US officials had previously told Reuters it was possible training would begin without that clarity.
Part of the US strategy, according to Obama administration documents seen by Reuters, is to pressure Assad by steadily increasing the opposition's prowess and territory under its control.
Proponents of the US military program note Assad is already facing growing pressure after government forces endured a series of recent setbacks on the battlefield and Islamist fighters edge closer to Assad's stronghold in the coastal areas.
