Washington - President Barack Obama has signed a covert document authorising US support for Syrian rebels locked in a battle to overthrow beleaguered President Bashar Assad, reports said on Wednesday.
The directive was contained in a "finding" - a device authorising clandestine action by the Central Intelligence Agency, NBC and CNN said, citing unidentified sources.
White House officials declined to comment on the reports but did not specifically rule out the idea that Washington was providing more intelligence support to anti-Assad forces than had previously been made public.
Washington has previously said that it is offering medical and communications assistance to Syrian rebels but declined to supply arms, warning it would be counter-productive to further "weaponise" the conflict.
Officials have confided they are wary of sending armaments to groups about which little is known and who some experts fear may eventually display extremist tendencies.
Reports of an increased US role with Syrian rebels came as the violent showdown in Syria appeared to be edging closer to an endgame, and clashes raged between government and opposition forces in Damascus and Aleppo.
No indication of policy change
They also coincided with rising political pressure on the White House to demonstrate more support for the opposition in Syria, despite US reluctance to become more directly involved in another Middle Eastern war.
It was not clear when Obama signed the secret order. There was no indication however that Washington had changed its overarching policy of not directly providing arms to the rebels.
On Monday, Obama spoke by telephone with Turkish Prime Minister Recep Tayyip Erdogan and the two leaders agreed to "accelerate a political transition in Syria", the White House said.
This "would include the departure of Bashar Assad and be responsive to the legitimate demands of the Syrian people", the statement said.
Syria is in the grip of a conflict now in its 17th month, triggered by Assad's brutal repression of a pro-democracy revolt. Western and Arab powers have called for him to step down and allow an orderly transition of power.
Washington has been frustrated by Russian and Chinese opposition to direct punitive action against Assad in the UN Security Council and appears now to be seeking ways outside the world body to pressure his regime.