The United States has begun distributing some weapons to the Syrian rebels, a spokesman for the Syrian Coalition of groups opposed to President Bashar Al-Assad said on Tuesday, after months of reported delays.

White House officials suggested in June that President Barack Obama had decided to provide military aid to the Syrian rebels, but in the months since, rebel leaders and US lawmakers have said no lethal assistance has arrived.

"The US is distributing non-lethal aid and ... some lethal assistance as well to the SMC (Supreme Military Council)," Saleh told a news conference, referring to the council that oversees operations of rebels loyal to General Salim Idriss.

The United States is providing lethal assistance "because they are sure that the mechanisms that the SMC has established are well tested and they will be sure that the weapons are not falling into the wrong hands," Saleh said.

He apparently referred to Washington's concerns that US arms could end up benefiting radical Islamist groups, such as the Al Nusra Front, active in northern Syria.

Saleh's comments at a Washington news conference may be the first public indication that US-provided military goods such as arms or ammunition are actually moving to anti-Assad forces.

One US government source said it was "unlikely" that any US-supplied arms were on the ground in the hands of Syrian rebels at this time, while not dismissing the possibility that such aid was in the works.

Separately, Secretary of State John Kerry said on Tuesday that Washington was trying to upgrade its support for the Syrian opposition.

"It is ramping up, but I can tell you that many of the items that people have complained were not getting (to) them are now getting to them," Kerry said in a Google+ Hangout interview. He declined to say what military items were arriving.

PLANNING FOR STRIKES

Rebel spokesman Saleh, who is based in Turkey, spoke at a news conference called to urge the US Congress to authorise Obama's proposal for limited military strikes in Syria following a chemical weapons attack on rebel areas outside Damascus on August 21 that the United States has blamed on Assad's forces.

Saleh said rebel military leaders were coordinating with the countries that might participate in a US-led strike.

He said the Supreme Military Council also had a plan to derive tactical benefits from the strikes if they do take place, such as by securing areas that are hit.

The chances of US military action have receded, however, since Russia offered a proposal on Monday for Syria to surrender its chemical weapons stockpile to international control.

Najib Ghadbian, the Syrian Coalition's representative in the United States, said the rebels favoured securing Syria's chemical weapons, but the Russian proposal should be amended to include accountability for those who have committed poison gas attacks.

"We will work with the international community," Ghadbian said, but added: "We don't' trust the Syrian regime. We don't trust the Russians."

After two years of balking at directly arming the Syrian opposition, the White House's pledge in June to provide military aid to the rebels, came as the US government said it had proof that Assad's forces had engaged in small-scale use of chemical weapons earlier this year.

Rebel sources recently confirmed receipt of arms such as anti-tank weapons financed by Saudi Arabia, which arrived last month through Jordan.

However, Republican and Democratic lawmakers on congressional intelligence committees held up the covert US effort for a while over concerns that the arms could end up in the hands of Islamist militants in Syria. In late July, lawmakers gave the plan the green light.

Last week, a former senior US official said a limited quantity of American arms had reached the rebels.

In the Google+ interview, Kerry said, "It is accurate to say that some things have not been getting to the opposition as rapidly as one would have hoped."

The CIA, which oversees the covert arming effort, had no comment on Saleh's remarks.

Lawmakers who favour arming the rebels, such as Republican Senators John McCain and Lindsey Graham and Democrat Carl Levin, have urged Obama to step up US support for the opposition as part of any plan to take military action in Syria. - Reuters