Bagram, May 27: The U.S. homeland security chief urged Pakistan's new government to tackle 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 pursues 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 in Islamabad, Pakistan's Prime Minister Yousuf Raza Gilani told a gathering of foreign diplomats Monday that his government was not negotiating with terrorists. He also said foreign forces _ a reference to American troops _ will not be allowed to operate in Pakistan.

``Pakistan's security forces will remain deployed to meet any threat posed by terrorists, and an effective mechanism will ensure implementation of the agreements reached with tribes,'' Gilani said, according to his office.

However, Pakistan's new leaders seem intent on a different course than the previous government led by allies of U.S.-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 U.S. base at Bagram in Afghanistan on Monday. ``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.

Chertoff said the U.S. has made a lot of progress in Afghanistan since 2001, when American-led forces ousted the Taliban militant movement for hosting al-Qaida chief Osama bin Laden.

But the country still requires dedication by U.S. and other allied forces, he said. Afghanistan has seen a sharp rise in violence in the last year, even as the U.S. and NATO have poured thousands of new troops into the country. The U.S. now has 33,000 troops in Afghanistan, the most ever.

NATO said this month that attacks in eastern Afghanistan _ where U.S. troops primarily operate _ have risen sharply in recent weeks. A spokesman said NATO was concerned that the peace deals in Pakistan were allowing militants to increase attacks over the border.

During a visit to Pakistan on Monday, British Defense Secretary Des Browne urged Pakistan and Afghanistan to cooperate in fighting militants. Browne said the threat posed by ``violent extremism'' cannot be tackled inside Afghanistan alone and requires a committed regional approach.