Pakistan's president signed an accord late Monday to put part of the country under sharia, Islamic law, as part of efforts to end a Taliban insurgency despite fears and criticism on Tuesday that the deal would encourage extremism.
Zardari, who vowed to stand up to the spread of militancy, faced pressure from conservatives and the main political party in the northwest, who said sharia was the only way to bring peace to Swat.
President Asif Ali Zardari's move formalized a controversial deal between a pro-Taliban cleric, who led thousands of supporters to fight against U.S. troops in Afghanistan and the government in North West Frontier Province.
The deal will apply to Malakand, a district of around three million people in the province that includes the Swat valley.
Supporters and critics
The central government lost control in Swat, a former ski resort and jewel in the crown of Pakistani tourism, after cleric Maulana Fazlullah launched a campaign to enforce the Taliban version of sharia.
Militants beheaded opponents, bombed schools and fought government forces, prompting tens of thousands of people to flee.
"God willing it will have a positive impact on the situation in Swat," said interior ministry chief Rehman Malik of the agreement.
"It is hoped that those who wanted this law in Swat will now surrender their arms and also bring the peace," he told reporters.
However, critics said Tuesday the deal opens the floodgates to the "Talibanization" of swathes in Pakistan, and the policy came under widespread criticism when a video emerged earlier this month of a veiled woman being flogged in public.
A spokesman for pro-Taliban cleric Soofi Mohammad, who signed the accord, said Zardari's signature would allow peace in Swat, just 160 kilometers (100 miles) away from the capital Islamabad.
"We will make all-out efforts to establish peace in the region. The Taliban have disarmed themselves and those who have not yet disarmed will do so soon," spokesman Amir Izzat Khan told AFP.
We will make all-out efforts to establish peace in the region. The Taliban have disarmed themselves and those who have not yet disarmed will do so soon
Spokesman Amir Izzat Khan
Pressure to fight insurgency
Pakistan, which U.S. President Barack Obama has put at the heart of the fight against al-Qaeda, has been under huge pressure to clamp down on extremists, but the government said negotiations are the best hope of restoring peace.
Its military is badly equipped for fighting an insurgency against its own people and the alliance with the United States is increasingly unpopular.
Much of the violence has been concentrated in the northwest, where Taliban and al-Qaeda extremists fled after the 2001 U.S.-led invasion of Afghanistan.
Militant attacks killed more than 1,700 people since July 2007, while more than 1,500 troops died at the hands of extremists since 2002.
But past peace deals between the government and pro-Taliban militants have quickly unraveled -- such as a deal in Swat last May.