WASHINGTON  — Al-Qaida’s second-in-command, Atiyah Abd al-Rahman, has been killed in Pakistan, delivering another big blow to a terrorist group that the U.S. believes to be on the verge of defeat, U.S. officials said Saturday.

The Libyan national had been the network’s operational leader before rising to al-Qaida’s No. 2 spot after the U.S. killed al-Qaida leader Osama bin Laden during a raid on his Pakistan compound in May.

Defense Secretary Leon Panetta said last month that al-Qaida’s defeat was within reach if the U.S. could mount a string of successful attacks on the group’s weakened leadership.

“Now is the moment, following what happened with bin Laden, to put maximum pressure on them,” Panetta said, “because I do believe that if we continue this effort we can really cripple al-Qaida as a major threat.”

Since bin Laden’s death, al-Qaida’s structure has been unsettled and U.S. officials have hoped to capitalize on that. The more uncertain the leadership, the harder it is for al-Qaida to operate covertly and plan attacks.

Bin Laden’s longtime deputy, Ayman al-Zawahiri, is running the group but is considered a divisive figure who lacks the founder’s charisma and ability to galvanize al-Qaida’s disparate franchises.

A U.S. official, who spoke on condition of anonymity to summarize the government’s intelligence on al-Rahman, said al-Rahman’s death will make it harder for Zawahiri to oversee what is considered an increasingly weakened organization.

“Zawahiri needed Atiyah’s experience and connections to help manage al-Qaida,” the official said.

Al-Rahman was killed Aug. 22 in the lawless Pakistani tribal region of Waziristan, according to a senior administration who also insisted on anonymity to discuss intelligence issues.

The official would not say how al-Rahman was killed. But his death came on the same day that a CIA drone strike was reported in Waziristan. Such strikes by unmanned aircraft are Washington’s weapon of choice for killing terrorists in the mountainous, hard-to-reach area along the Pakistan-Afghanistan border.

Rahman has been thought to be dead before. Last year, there were reports that Rahman was killed in a drone strike but neither senior U.S. administration officials nor al-Qaida ever confirmed them.

Al-Rahman, believed to be in his mid-30s, was a close confidant of bin Laden and once served as bin Laden’s emissary to Iran.

Al-Rahman was allowed to move freely in and out of Iran as part of that arrangement and has been operating out of Waziristan for some time, officials have said.

Born in Libya, al-Rahman joined bin Laden as a teenager in Afghanistan to fight the Soviet Union.

After Navy SEALs killed bin Laden, they found evidence of al-Rahman’s role as operational chief, U.S. officials have said.

Falcon High School graduate Danny Pate needs a new team next year, as California-based HTC-Highroad is folding after this season because of financial struggles. Pate had a 41st-place finish Friday in an 82.8-mile trek from Avon to Steamboat Springs at the USA Pro Cycling Challenge to improve to 73rd in the overall with two stages remaining. Photo by THE ASSOCIATED PRESS

MICHEL SPINGLER