ISLAMABAD, Pakistan – Videos released Monday of a Pakistani Taliban chief thought to have been killed by a U.S. drone strike in January reveal that he not only is alive but has apparently expanded his group’s ambitions.

In the videos, Hakimullah Mehsud vows attacks on U.S. cities, which he says his suicide bombers have already penetrated.

The videos provide the first solid evidence that he survived the missile strike, and they come after the Pakistani Taliban’s widely dismissed claim of responsibility for the failed attack in New York’s Times Square. In that case, authorities were zeroing in on a naturalized U.S. citizen from Pakistan, though any connections to extremist groups were unknown.

Mehsud’s profession of global goals was a departure for the Pakistani Taliban, a motley militant network. The group is linked to al-Qaida, but it has displayed no ability to carry out attacks outside Pakistan and Afghanistan. Last year, it falsely asserted responsibility for a shooting in New York.

Intelligence officials and analysts said the threats against the United States probably represented more of that same bravado, meant to rally the troops of a weakened organization — but also prove that it has not been beaten.

“These guys bluster a lot,” said Imtiaz Gul, chairman of the Center for Research and Security Studies in Islamabad. “This would be one way to inject some sort of confidence, to revitalize the organization, by sending this message out that ‘we are very much around.’ “

The Pakistani Taliban has led a sustained campaign of bombings in Pakistan over the past three years, but a recent army offensive in its South Waziristan sanctuary pushed many of its fighters and leaders to North Waziristan. Attacks are now more sporadic but have recently included high-profile targets, including the U.S. Consulate in the northwestern city of Peshawar.

On Monday, Pakistani intelligence and military officials said that Mehsud’s threats might also have been intended to pressure the army to open a new front in North Waziristan in hopes it would become overstretched and lose control of South Waziristan.

U.S. officials also want Pakistan to target North Waziristan, a haven for al-Qaida and Afghan Taliban fighters who stage attacks in Afghanistan, but Pakistan is reluctant.

The officials said the South Waziristan operation had eliminated the Taliban’s training infrastructure, making it unlikely that the group could plan strikes in the United States or that it orchestrated the failed Times Square attack.

“These days, most of their trained suicide bombers are being killed in Pakistan,” said one intelligence official based in Peshawar.