WASHINGTON, Aug. 8 (Xinhua) -- Former U.S. ambassador the United Nations Zalmay Khalilzad on Wednesday urged for greater U.S. involvement in Syria, including forming a "coalition of the relevant," arming the rebels and seeking an understanding with Russia.

Writing in an op-ed article published in The Washington Post, Khalilzad, who served as the U.S. envoy to the UN during 2007 to 2009, said the U.S. has a window to facilitate an orderly transition in Syria without deploying military force.

"But the window is narrowing - and the Obama administration will need to adjust its political strategy to succeed," he warned.

Khalilzad noted that the current U.S. focus on engaging the UN Security Council and the Friends of Syria, a French-created group of 88 states and several international organizations, has failed to make progress, while providing only non-lethal assistance to the Syrian opposition "is prolonging unfavorable trends on the battlefield."

The former envoy put up five proposals on how the United States can facilitate "an orderly transition without deploying force," including forming a "coalition of the relevant," appointing a special envoy to work with the coalition to help the Syrian opposition, directly arming the Syrian rebels, seeking understanding with Russia, and letting the UN play a major role in Syria's political transition.

He said the "coalition of the relevant" refers to a select group of like-minded countries "that have significant leverage and influence in Syria."

It should comprise not only the UN, the Friends of Syria and NATO, but also Britain, France, Turkey, Saudi Arabia, Jordan, Qatar and other Gulf states.

He said a special envoy should be appointed to work with the coalition in organizing the Syrian opposition into "a broad-based front that provides a vehicle for a stable transition, attracts support from Syrians fearful of regime change, and co-opts elements of the Assad regime."

Washington should also directly provide military support to the Syrian opposition, which will give the leverage necessary to shape a united front politically, Khalilzad suggested.

"Direct U.S. involvement improves the likelihood that arms are distributed to Syrians who embrace a moderate and inclusive order, which would tilt the balance of power away from sectarian and Islamist groups," he said.

Khalilzad also proposed the Obama administration seek an understanding with Russia, by reassuring Moscow that its core strategic and business interests can be protected in a new Syria.

"In exchange, Russia should be expected to refrain from vetoing U.S.-backed Security Council resolutions, to cease all support to the Assad regime and to pressure Bashar al-Assad in Syria," he said.

He added that Washington "should remain open to an active UN role in finalizing a transitional road map once the conditions for a new order are in place," as it has in post-Taliban Afghanistan.

The Obama administration has so far refrained from providing direct military aid to Syrian rebels due to worries about many unpredictabilities, despite that the conflict there has been escalating in recent weeks. Enditem