WASHINGTON: The United States can still work out a deal with a willing partner in Afghanistan, a senior US official said on Friday as lawmakers and military leaders warned that pulling out all troops from the war-ravaged country could bring the terrorists back.

US Special Representative for Afghanistan and Pakistan James Dobbins told a gathering in Washington that although President Barack Obama ordered the Pentagon earlier this week to prepare for a complete withdrawal from Afghanistan, he did not close all doors.

“President Obama’s decision to leave open the possibility of concluding the necessary agreement with a willing partner later this year provides hope that this all can still be worked out,” Mr Dobbins said.

President Obama had blamed Afghan President Hamid Karzai’s continued refusal to sign a bilateral security agreement for his decision to prepare for a final pullout.

But his order alarmed many in Washington and at a hearing of the House Armed Services Committee on Thursday, US Admiral William McRaven warned: “If we do go to zero, and there is no special operations component left in Afghanistan, it will certainly make it more difficult to be able to deal with ... the potential resurgence of Al Qaeda in the area.”

Admiral McRaven, who heads the US Special Operations Command, oversaw the 2011 raid that killed Al Qaeda founder Osama bin Laden in his compound in Abbottabad.

He said the danger posed by Al Qaeda is “inherent within the Federally Administered Tribal Areas (in Pakistan), and in the northern part of Afghanistan, in Kunar and Nuristan (provinces)”.

“Afghanistan is the birthplace of Al Qaeda and is unique in its vulnerability to once again becoming a safe haven for terrorists if a strong government is not supported,” warned House Armed Services Committee Chairman Howard McKeon.

Meanwhile, the AP has carried a report saying that US official believed Al Qaeda’s Afghanistan leader is laying the groundwork to re-launch his war-shattered organisation once the United States and international forces withdraw from the country.

The report also quoted House Intelligence Committee Chairman Mike Rogers as saying that the number of Al Qaeda members in Afghanistan has risen. “I think most are waiting for the US to fully pull out by 2014,” he warned.

US military and intelligence officials said to prevent Al Qaeda from regrouping, they needed to continue to fly drones and jets from at least one air base in Afghanistan but this would not be possible if a security agreement was not signed.

But Admiral McRaven told the House panel that despite these alarm bells, the core Al Qaeda has gotten markedly weaker.

“The threat that was emanating out of the Federally Administered Tribal Areas with the support of other government agencies and the support of the Pakistanis, we have really decimated the core Al Qaeda. So I would tell you that threat is significantly decreased,” he said.

Ambassador Dobbins said that while most Americans were tired of the Afghan conflict and believed that the results had not justified the cost, they “also recognise the need to withdraw gradually and responsibly”.