ISLAMABAD, Pakistan - A top U.S. senator yesterday urged Pakistan to "ratchet up" its sense of urgency in battling the spreading extremism in its northwest, even as the government defended a deal to impose Islamic law in a swath of the region to achieve peace with the Taliban.

Sen. John Kerry expressed reservations about the peace pact in the Swat Valley, hours after a hard-line cleric who mediated the deal indicated it would protect extremists accused of killings from prosecution.

Kerry, chairman of the Senate Foreign Relations Committee, is spearheading a bill to increase nonmilitary aid to Pakistan, a multibillion-dollar effort to strengthen sectors such as the economy and education in part to lessen the allure of extremism in the impoverished Muslim-majority nation of 170 million.

The senator told reporters the Pakistani government had to make some "basic decisions," including where and how much of its army it would deploy against al-Qaeda and Taliban fighters, who are primarily based along its northwest border with Afghanistan. The army has tens of thousands of troops in the northwest but has long devoted far more resources to its eastern border with longtime rival India.

"I don't think that the effort [against extremists] has been resourced the way that it needs to be," Kerry said, adding later: "The government has to ratchet up the urgency."

Pakistan's beleaguered, U.S.-allied government has tried both carrots and sticks in dealing with the insurgency, even as it has been distracted by a host of issues, including a faltering economy and political feuds. In Swat, a valley that once attracted many tourists, 18 months of bloodshed prompted the provincial government in February to agree to impose Islamic law there to achieve peace. The Taliban agreed to a cease-fire.

After weeks of foot-dragging, Pakistani President Asif Ali Zardari approved the regulation late Monday only after Parliament voted unanimously to adopt the resolution.

The deal covers the Malakand division of Pakistan's North West Frontier Province, a largely conservative region that stretches north along the Afghan border. The Swat Valley section lies less than 100 miles from the capital, Islamabad, and is believed to be largely under Taliban control.

Defenders say the deal will drain public support for extremists who have hijacked long-standing calls in Swat for reform of Pakistan's snail-paced justice system.

Critics worry that it rewards hard-liners who have beheaded political opponents and burned scores of schools for girls in the name of Islam - and that it will encourage similar demands in other parts of the nuclear-armed country.

White House press secretary Robert Gibbs said the Obama administration believed security could not be brought about with "less democracy and less human rights" and said strict Islamic law in the Swat Valley "goes against both of those principles."

Hard-line cleric Sufi Muhammad brokered the deal, whose terms remain murky. Asked yesterday whether the new courts would hear complaints from Swat residents about the extremists, Muhammad strongly suggested they could not.

"We intend to bury the past," he said. "Past things will be left behind, and we will go for a new life in peace."

Federal Information Minister Qamar Zaman Kaira insisted the deal would not lead to a version of Islamic law like that upheld by the former Taliban regime in Afghanistan.

A spokesman for the Taliban said the militants would cooperate. If the law is quickly implemented, "the world will see how much peace and prosperity comes to this region," Muslim Khan said. He announced late yesterday that the militants would observe a ban on the "unnecessary" display of arms in Swat.

Many observers doubt the Swat Taliban's ambitions will end at the valley's borders. Taliban extremists from Swat recently made a violent push into the neighboring Buner region, and Muhammad has repeatedly denounced Pakistan's democratic system as being against Islam - a view shared by the extremist groups blamed for the country's rising violence.