SARAROGHA, Pakistan (AP) — Flanked by heavily armed fighters, the new leader of the Pakistani Taliban sat on a blue blanket, amiable and relaxed as he cracked jokes and mixed in threats of vengeance for deadly U.S. airstrikes.

One day later, a suicide bomber attacked a U.N. office in Islamabad.

Hakimullah Mehsud met with reporters Sunday for the first time since winning control of the militant group, quashing speculation that he had been slain in a succession struggle following the killing of his predecessor in a U.S. drone attack.

He also described his group’s relationship to al-Qaida as one of “love and affection.” Osama bin Laden and other top al-Qaida leaders are believed to be hiding out in the remote border region with Afghanistan, possibly in territory controlled by Hakimullah.

The militant vowed to retaliate against the U.S. and Pakistan for deadly attacks on his allies and said his fighters will repel an anticipated Pakistani offensive into his stronghold.Hakimullah made his threat of vengeance hours before a suicide bomber disguised as a security officer killed five people at a U.N. office in Islamabad on Monday.

There was no immediate claim of responsibility, but authorities blamed Islamic militants.Pakistani Interior Minister Rehman Malik has said several times that officials believed Hakimullah — and possibly his deputy, Waliur Rehman — had been killed in fighting over who would replace Baitullah Mehsud after his Aug. 5 death in a missile strike.

Malik said that Hakimullah was being impersonated by his brother, including in calls to media organizations.

Western diplomats in Islamabad had also said their intelligence indicated he may have been killed, while Western media reports over the weekend quoted American officials as saying they believed he may be dead.

Hakimullah was very much alive, speaking calmly as he sat under a tree on a blanket surrounded by top Taliban commanders, including Waliur Rehman, in a show of unity in South Waziristan, where the Pakistani state and security forces have little or no presence.

Also present were Qari Hussain, the head of the Taliban’s suicide bomb faction, and Azam Tariq, a Taliban spokesman.

He told five Pakistani reporters, including one from The Associated Press, that the group’s leadership remained intact and unified.

“We all are sitting before you, which proves all the news about myself … was totally baseless and false,” he said.

Pakistani security authorities were not immediately available for comment.

Pakistan has largely beaten back a Taliban insurgency in the northwestern Swat Valley in recent months and intelligence officials say the country is preparing a major offensive against al-Qaida and the Taliban in South Waziristan.

The military has been blockading the region and seeking to encourage other tribes to rise up against Hakimullah.

Hakimullah said his forces were ready for such an attack, which would likely be far tougher than the Swat campaign.

The army has been beaten back there three times since 2004. Analysts say some 10,000 well-armed militants, including foreign fighters, are in the mountainous region and well dug in.

“We are fully prepared for that operation and we will give full proof of those preparations once the offensive is launched,” he said.

On the drive to and from the interview, the AP reporter could see fighters taking up positions at key vantage points. Residents said the militants were digging trenches along routes the army was expected to travel.

Fearing the coming offensive, civilians were fleeing the area via backroads and traveling at night because the military had already sealed most of the main routes out.

While Baitullah avoided the glare of media and was only photographed once — from a side angle — Hakimullah showed no such modesty.

At one point, he pulled out a laptop to show his guests an Afghan comedian’s standup routine about jihadi — or holy war — groups.

On the serious side, he also showed pre-attack video testimony made by a suicide bomber.

Hakimullah spoke flanked by fighters wielding automatic rifles and rocket-propelled grenades.

He agreed to be interviewed on condition his comments not be published until the reporters left the area Monday.

U.S. officials are watching closely to see whether Hakimullah will direct more fighters across the border where U.S. and NATO forces face attacks by insurgents.

Baitullah was believed to have mainly concentrated on attacking Pakistani targets.Hakimullah did not address that issue directly, only saying there were no “difference between Taliban of Afghanistan and Pakistan.”

He said the Pakistani Taliban were fighting for the imposition of Islamic law in Pakistan and to rid it from the “clutches of the Americans and the Jews.”

“For this very purpose, we will enhance and prolong our jihadi efforts,” he said.

Hakimullah also introduced a man he identified as Qari Mohammad Zafar, who has a $5 million bounty on his head from the U.S. Justice Department in the 2002 bombing of the U.S. consulate in Karachi that killed three Pakistanis and a U.S. diplomat.

“See, we have such people with us. And they are saying that we have differences. It is an example that we are united,” he said.

He vowed his forces would avenge Baitullah Mehsud’s killing and would strike back at Pakistan and the U.S. for the increasing airstrikes.

Unmanned drones have carried out more than 70 missile strikes in northwestern Pakistan in the last year in a covert program, killing several militant commanders along with sympathizers and civilians.

The Pakistani government publicly protests the attacks but is widely believed to sanction them and provide intelligence for at least some.

“There is no doubt that American spy planes are being used in these attacks, but we know all the intelligence is being provided by Pakistan,” Hakimullah said.

“We have taken revenge for the past attacks and we will definitely take revenge for the remaining drone attacks.”

• Ishtiaq Mahsud