Syrian opposition forces began receiving weapons from the CIA about two weeks ago, some three months after the Obama administration decided to provide them with lethal assistance, US officials said Thursday.

The shipments of light weapons began arriving days after an alleged chemical attack on August 21 that the US says killed over 1,400 people. That attack prompted Washington to mull military intervention, although plans for a strike on Syria have been shelved for the time being in favor of Russian-brokered diplomatic efforts.

In June, the US announced that it would begin to arm the rebels, with President Barack Obama saying he had “conclusive evidence” that Syrian President Bashar Assad had employed chemical weapons in smaller scale attacks several times during the year. The US was initially disinclined to throw its weight behind the rebels due to the dominance of al-Qaeda-allied groups among Syrian opposition forces.

Russia, while reportedly increasing the volume of weapons it has been delivering to the Syrian regime, has adamantly opposed American intervention in the two-and-a-half-year Syrian civil war. In an op-ed piece published Wednesday in The New York Times, Russian President Vladimir Putin wrote that a US strike would create more victims, spread the conflict beyond Syria, and potentially “unleash a new wave of terrorism.”

American lawmakers have been divided on the question whether or not to intervene in the Syrian civil war, which has now raged for over two-and-a-half years, claiming over 100,000 lives and displacing some two million Syrians.

Recent arms shipment to the rebels mark the first time since June, when the decision to arm the rebels was made, that the US has actually sent weapons to opposition forces.

In addition to the weapons, the US has provided Syrian rebels with vehicles, advanced communications equipment, combat medical kits, and training. A first unit of CIA-trained rebels entered Syria earlier this month, according to reports.

Earlier this week, US Secretary of State John Kerry, in an apparent offhand remark, suggested that direct US military intervention could be averted if Syria agreed to place all of its chemical weapons under international control. Russia, which has long been an ally of the Assad regime, pitched the idea to Syria, whose foreign minister, Walid Moallem, welcomed the proposal.

The initiative prompted Obama to announce that he would be putting on the back burner plans to appeal to US lawmakers for approval for a military strike.