PESHAWAR, Pakistan (CNN) -- The Pakistani Taliban will avenge the group's No. 2 leader, who was slain Wednesday in a drone strike, and won't listen to government peace initiatives, a spokesman said Thursday.

Ehsanullah Ehsan, the group's spokesman, told CNN the group holds the Pakistani government responsible for the death of Wali-Ur Rehman Mehsud.

Rehman is one of seven people slain when a drone struck a target near the town of Miranshah, according to a local official and an intelligence official. The target is in the North Waziristan district of Pakistan's tribal region -- a rugged area with a significant population of militant groups.

The Pakistani Taliban will not accept any offer from the government for a peace dialogue, Ehsan said. Nawaz Sharif, the Pakistani politician who is expected to serve as the next prime minister, has broached the issue of engaging in peace talks with the Pakistani Taliban.

Militants in the tribal region, including the Pakistani Taliban, long have been conducting an insurgency against the Pakistani government.

Rehman -- now buried in a secret North Waziristan location, Ehsan said -- was wanted by the United States on suspicion of being involved in the December 2009 suicide bomb attack that killed seven CIA employees at Forward Operating Base Chapman in Khost, Afghanistan, according to a publication by the U.S. National Counterterrorism Center.

The publication, which described him as the Pakistan Taliban's No. 2 leader and chief military strategist, and said he participated in cross-border attacks in Afghanistan against U.S. and NATO personnel. He was second in command to Hakimullah Mehsud.

Rehman was killed along with his close aide, Fakhar-ul-Islam, and two Uzbek nationals whose identities the sources didn't know.

The United States has long conducted drone strikes in its fight against suspected Taliban and Pakistani jihadist groups in Pakistan near the Afghan border. Before this week, the last reported drone strike in Pakistan was in mid-April. The latest strike was the first known hit since Pakistan held general elections on May 11 and since U.S. President Barack Obama announced his new counterterrorism policy last week.

White House spokesman Jay Carney told reporters Wednesday that he couldn't confirm reports of Rehman's death, but he said the militant was wanted for the Khost incident and mentioned his participation in attacks. "It's important to note who this individual is," he said.

Drone strikes have become controversial and unpopular because they have killed civilians, and Pakistan has said it has "serious concerns" over the latest attack.

Pakistan, which describes itself as a front-line state in the fight against terrorism, said it has "consistently maintained that the drone strikes are counterproductive, entail loss of innocent civilian lives, have human rights and humanitarian implications and violate the principles of national sovereignty, territorial integrity and international law."

When Obama discussed drone strikes last week in his counterterrorism address, he said they must be used with more temperance and caution. But, he said, they remain a necessary tool to take on terrorists.

CNN's Zahir Shah Sherazi reported from Peshawar and Joe Sterling wrote and reported in Atlanta.