ISLAMABAD (Reuters) - Pakistani forces battled Taliban fighters on Monday as the militants denounced the army and government as U.S. stooges and said a peace pact would end unless the government halted its offensive.
President Asif Ali Zardari is due to meet U.S. President Barack Obama and Afghan President Hamid Karzai in Washington on May 6-7. The pact in the Swat valley is expected to figure in their security talks.
The February pact and spreading Taliban influence have raised alarm in the United States about the ability of nuclear-armed Pakistan -- which has a vital role in efforts to stabilise Afghanistan -- to stand up to the militants.
Here are some questions and answers about the offensive launched on April 26, and background to the Swat pact.
Failure to stem the Taliban's creeping advance from enclaves in ethnic Pashtun tribal areas on the Afghan border sparked worry among both Pakistanis and Western allies that militants were close to the gateways to Islamabad.
A military spokesman said a few hundred militants in the mountains never posed a real threat to the capital. But some security analysts say the guerrillas could have used Buner as a jumping-off point to strike at Tarbela, a dam that provides water and electricity to much of the country. The militants have also moved closer to a road running north to China.
Before the military offensive in Buner, Western allies, who need Pakistani help to defeat al Qaeda and stabilise Afghanistan, worried the government seemed too willing to appease militants.
While Swat, about 130 km (80 miles) northwest of Islamabad, is not on the Afghan border, Western countries with troops in Afghanistan fear the area could become a bastion for militants fighting in both Afghanistan and Pakistan.
Obama said last week he was confident about the security of Pakistan's nuclear arsenal but the New York Times reported growing U.S. concern militants might try to snatch a weapon in transit or insert sympathisers into laboratories or fuel-production facilities.
The fighting came on the heels of a visit to Islamabad by Admiral Mike Mullen, the chairman of the U.S. Joint Chiefs of Staff, who may have played a role in persuading the weak civilian-led government to act, and shortly before the talks in Washington where Zardari is likely to press for more U.S. military and economic aid.
Washington is considering rushing hundreds of millions of dollars in emergency aid, the U.S. Senate's second-ranking Republican, Jon Kyl of Arizona, told reporters.
U.S. officials have applauded the military action in Buner and urged the Pakistan military to keep the Taliban on the run.
The deal was struck after consultations with the army.
Army chief General Ashfaq Kayani said the military halted its operations in Swat early last year in order to give politicians space to negotiate, but added the army would not allow militants to impose their will on the country.
Kayani has to counter a general perception the army, whose main focus has been a perceived threat from old rival India, is demoralised and reluctant to fight Pakistani Muslims in Swat, although security forces defeated the Taliban in the Bajaur tribal area on the Afghan border in March.
Many people from Swat were caught up in the siege of Islamabad's Red Mosque in July 2007, which commandos stormed to put down a militant movement, resulting in at least 100 deaths.
Violence flared in Swat later that year, and while military operations pushed the Taliban back, they regrouped as soon as the army relented to allow politicians space to negotiate a peace.
The North West Frontier Province government led by the Awami National Party (ANP), an ethnic Pashtun party allied to Zardari, struck a deal with a radical cleric in February to impose sharia law in the hope of ending violence.
Zardari sanctioned the imposition of Islamic law in Malakand after parliament passed a resolution last month. Days later, Taliban fighters entered Buner and nearby Shangla district, raising alarm at home and in the West.
Aides say Zardari was reluctant to sign the deal and referred the issue to the parliament after the ANP threatened to leave the federal coalition government.