WASHINGTON -- Gen. David Petraeus, head of U.S. Central Command, ruled out sending U.S. troops to Yemen, where the al Qaeda affiliate that has claimed responsibility for the attempted Christmas Day airline bombing is based.
 

Speaking in an interview with CNN, Gen. Petraeus said the U.S. would double security aid to Yemen, to more than $150 million from $70 million currently. U.S. and British officials have announced a plan to jointly fund a new Yemeni counterterrorism force in the wake of the failed attack on a Detroit-bound Northwest Airlines flight.
 

On Friday, the suspect in the attack, Nigerian Umar Farouk Abdulmutallab, pleaded not guilty in a federal court in Detroit to allegedly trying to blow up the plane by igniting explosives hidden under his clothes. Representatives of the group, al Qaeda in the Arabian Peninsula, based in Yemen, have claimed responsibility for organizing the attack.
 

Last week, Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, appeared to rule out direct U.S. military action in Yemen. Adm. Mullen told students at the George Washington University in Washington that the U.S. would focus its efforts on helping fund and train Yemeni security forces, some of which are already being mentored by small teams of elite American Special Operations forces.
 

The failed terrorist attack continued to draw scrutiny from lawmakers on Sunday, with Sen. Joseph Lieberman (I., Conn.) saying U.S. officials should be held "accountable" for intelligence lapses that had resulted in the alleged bomber being able to board the aircraft.
 

President Barack Obama has faulted U.S. intelligence agencies for failing to stop the alleged bomber, but hasn't announced any plans to fire or demote anyone over what he has described as a systemic failure. U.S. intelligence agencies had received several warnings about a possible plot before the attempted attack, including from Mr. Abdulmutallab's father, a high-level Nigerian banking official who told U.S. Embassy officials in Nigeria that his son had become radicalized and disappeared.
 

Mr. Lieberman, speaking on CNN's "State of the Union," said both by the Department of State and the National Counterterrorism Center had made mistakes in the case. "Something went wrong," he said. "If human errors were made, I think some of the humans who made those errors have to be disciplined so that they never happen again."
 

Elsewhere Sunday, Yemen's president said he is ready to open a dialogue with al Qaeda fighters who lay down their weapons and renounce violence, despite U.S. pressure to crack down on the terror group.

The U.S. has complained in the past that Yemen struck deals with al Qaeda fighters and freed them from prison after they promised not to engage in terrorism. Some later broke those promises and are now believed to be active in al Qaeda's offshoot in Yemen.
 

President Ali Abdullah Saleh vowed that his government was "determined to stand up to the challenges" of al Qaeda and that his security forces will track down as many al Qaeda fighters as possible among those who refuse to stop violence.

But he left the door open for negotiations. "Dialogue is the best way ... even with al Qaeda, if they set aside their weapons and return to reason," he said in an interview with Abu Dhabi TV aired late Saturday. "We are ready to reach understanding with anyone who renounces violence and terrorism." (WSJ)