A high-ranking Al Qaeda figure reportedly was killed Thursday in a U.S. drone aircraft attack in north Pakistan.

The attack, first reported by NBC News, was officially denied by Pakistani officials, though sources told Fox News that neither Usama bin Laden or Ayman al-Zawahiri were among those killed.

Pakistani media report six militants were killed in the attack, including four foreign fighters, a classification in the tribal areas that typically refers to Al Qaeda.

The attack was part of the expanded use of Predator drones recently authorized by the White House, sources told Fox News, though the drone attacks, which began during the Bush Administration, never have been officially confirmed because of political sensitivity in Pakistan.

The Obama administration reportedly is talking with Pakistan about expanding the program from Waziristan to Baluchistan, a controversial move since it is outside the tribal areas near the Afghanistan border.

Baluchistan is where Afghan Taliban leaders are believed to be hiding.

The administration's decision corresponds with Obama's announcement last week to send 30,000 additional troops to Afghanistan.

Meanwhile, lawmakers lashed out at Pakistan last week as an unreliable ally in the Afghan war that could spare the U.S. its bruising fight with Al Qaeda if it wanted.

"They don't seem to want a strategic relationship," New Jersey Democratic Sen. Bob Menendez said of the government in Islamabad. "They want the money. They want the equipment. But at the end of the day, they don't want a relationship that costs them too much."

A crucial ally in fighting the Al Qaeda terrorist network, Pakistan is also a major recipient of U.S. aid. President Obama and Congress recently approved a $7.5 billion aid package for economic and social programs in Pakistan in a bid to strengthen the civilian government there.

But many in Congress have grown skeptical that Islamabad is doing all it can to drive out Al Qaeda forces hiding along its mountainous Afghan border.

Fox News' Catherine Herridge and The Associated Press contributed to this report.