Top US military chief in Islamabad as drone kills 16

The dead in the drone attack were all Islamist fighters, according to military official. South Waziristan, which is on the border with Afghanistan, was the scene of an anti-Taliban offensive last year.

Mullen is to meet Pakistan’s military head General Ashfaq Kayani – the 19th time the two have met, according to Mullen’s aides - as well as US officers overseeing military work with the Pakistanis.

In Delhi, before leaving for Islamabad, Mullen said that he considers tackling the North Waziristan-based Haqqani network as “a very, very strong priority”, dubbing it ‘the most lethal network”.

The group was founded by Afghan warlord and former anti-Soviet fighter Jalaluddin Haqqani and is run by his son, Sirajuddin. It is believed to have been responsible for many of the most effective attacks against foreign troops and targets associated with President Hamid Karzai’s government.

Mullen also said that Pakistan’s intelligence service, the ISI, needs to “fundamentally change” is strategy, following reports that its long involvement with the Taliban and other armed Islamist groups continues.

Former Pakistani military chief General Mirza Aslam Beg refers to groups such as the Haqqani network as "the resistance" and predicts that they will not be defeated militarily.

“Despite of all the vigilance, all the intelligence, all the strikes being launched against them, with every passing day, they are becoming more active, more effective,” he told RFI. "There’s a new generation that have grown under the shadow of war. They know nothing but war.”

Beg wants the Afghan and Pakistani government to sue for peace with the armed groups.

“I think the time has come when it must be realised that we have to find peace with them,” he says.

Prime Minister Yousouf Raza Gilani on Thursday extended Kayani’s term for three years, a move which US officials welcomed because of anti-Taliban offensives launched under his command.

Mullen will also take an aerial tour to an unspecified location in the north.

Meanwhile in the southern city of Karachi, an attack on a bus is reported to have wounded seven people.