Islamabad: Pakistan is determined to stop militants crossing its border to fight Western troops in Afghanistan and is activating tribal leaders to squeeze out the militants, a government official said on Monday.

Pakistan's new civilian government, led by the party of assassinated former prime minister Benazir Bhutto, is pursuing talks with militants to end a wave of violence that has raised concern about prospects for the nuclear-armed US ally.

But that has raised alarm among Pakistan's allies, especially those with troops in Afghanistan, who fear pacts on the Pakistani side of the border only help militants focus efforts on attacks across in Afghanistan.

Nato's force in Afghanistan said recently the peace talks the new Pakistani government had launched had led to an increase in attacks in Afghanistan.

Committed

But a top Pakistani government official overseeing security policy on the Afghan border defended the pacts and said Pakistan was committed to Afghanistan's security.

"Pakistan is fully committed to interdicting cross-border movement of terrorists," Owais Ahmad Gani, governor of the North West Frontier Province, said.

A re-think was needed in the war against the Taliban, Gani said. "This war against these extremists ... has now entered the seventh year and I feel that we need to actively review our strategies," he said.

"What we need to do is to reduce the space available to these negative forces."

Many Al Qaida and Taliban militants fled to Pakistan's border lands, that have never come under the full control of any government, after US-led forces ousted the Taliban in 2001.

There they were welcomed by the conservative Pashtun tribes who, since the war against Soviet forces in Afghanistan in the 1980s, had given refuge to Islamist fighters battling foreigners in Afghanistan.

Winning over the tribes was crucial, Gani said.

The government was not talking to the militants but to the Pashtun elders in the border areas in an effort to get them to exert their authority and isolate the militants, he said.

"We are talking to the majority tribes, their leaders, because it is their area and they are citizens of Pakistan and we are activating them so that they take control of their area and they reduce the space available to these militants," he said.

Bagram, Afghanistan (AP) The US homeland security chief called on Pakistan's new government yesterday to strike back against terrorism in its regions bordering Afghanistan or face more attacks of the kind that killed ex-premier Benazir Bhutto.

Michael Chertoff's comments come as the Pakistani government is pursuing peace deals with militant groups.

The United States and Nato have expressed concern that such deals give extremists space to plan and execute attacks on foreign forces in Afghanistan, where American troops have seen a rise in violence in recent weeks.

But Pakistan's new leaders appear determined to set a different course than the previous government led by allies of US-backed President Pervez Musharraf, which relied heavily on military force to battle extremist fighters.

Militancy in the border areas is a threat to both countries, and Pakistan should "make sure it asserts control and strikes back against terrorism" on its side, Chertoff told journalists after a citizenship ceremony at the US base at Bagram in Afghanistan.

"Otherwise they're going to see more of the kinds of tragedies that we saw with [former Pakistani Prime Minister] Benazir Bhutto, who was assassinated, or some of the bombings we've seen over the last few months in Pakistan as well as Afghanistan," he said.

Pakistan's foreign office spokesman declined to comment on Chertoff's remarks.