Emilio Morenatti, Associated Press
A Pakistani police officer holds a gun as worshippers pray Friday at the site of a blast last weekend at a Marriott hotel in Islamabad. Pakistan is still reeling from the explosion, which killed 53 people.

ISLAMABAD, Pakistan — Pakistan sought to reassure Washington on Friday that it remained an ally in fighting terrorism, but it also warned the U.S. to stay out of Pakistani territory while hunting down militants along the volatile border with Afghanistan.

Emphasizing that it doesn't need American firepower, a Pakistani general said an offensive along the frontier has killed more than 1,000 militants and predicted the region would be "stabilized" within two months.

He also showed photos of militant tunnel systems and trenches in Bajur, suggesting more tough fighting ahead in an area that is considered a likely hiding place for Osama bin Laden and other al-Qaida leaders.

Washington has launched a flurry of missiles and a ground assault on targets within Pakistan recently, infuriating ordinary Pakistanis and their leaders.

In the first serious exchange with Pakistani forces acknowledged by the U.S., American helicopters and Pakistani ground troops briefly traded fire Thursday on the border. The aircraft were not hit and no one was hurt.

U.S. officials said the two choppers were inside Afghanistan when the troops opened fire. Pakistan insisted the aircraft had crossed the ill-defined and contested border.

Pakistani government spokesman Akram Shaheedi urged U.S.-led coalition forces "not to violate (the) territorial sovereignty of Pakistan as it is counterproductive to the war on terror."

"It has been Pakistan's policy that we will not allow anyone to violate our sovereignty, and we will continue to defend our territorial sovereignty," he said.

President Asif Ali Zardari addressed the U.N. General Assembly on Thursday and warned that Pakistan cannot allow its territory to "be violated by our friends." But he struck a more conciliatory note Friday at a brief appearance alongside Secretary of State Condoleezza Rice.

"I look at U.S. support as a blessing. I look at the world support as a blessing to Pakistan," Zardari said.

Rice did not answer when asked about the border clash, but expressed unwavering U.S. support for Pakistan.

"We know that Pakistan has many challenges in security, in the economy, and in bringing stability to this young democracy," she said. "But we hope that the president and Pakistani people were assured today that the international community will be by their side as they make difficult decisions and move toward a more stable and prosperous Pakistan."

Analysts said while the incident had added to tensions, there was little chance it would herald a wider breakdown, noting that both parties

needed each other.

Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, said in Washington that Pakistani military leaders have reassured him they have no intention of using force against U.S. troops along the border.

Mullen said he received the reassurance last week while visiting Pakistan. He said he has no reason to believe the relationship has changed because of Thursday's incident.

"I am hard-pressed to see a set of circumstances where there would be any kind of sustained fight between two allies," he said.

The U.S. and NATO sends fuel and other supplies through Pakistan to its troops in Afghanistan, while Pakistan requires help from the U.S. and other Western powers to pull out of a crippling economic crisis.

Thursday's clash drew praise from fiercely anti-American tribesman.

"Pakistan should have reacted against the Americans like this earlier," said Mushtaq Khan. "They started late, but still it is a welcome step."

Sarwar Shah, a 45-year-old bus driver who witnessed the incident, said he was happy to see the Pakistan army firing at the helicopters. "If the army needs our help, we will help it against the Americans," Shah said.

Pakistani officials have long warned that unilateral U.S. actions in the tribal zone risk alienating residents whose cooperation they need in battling the insurgents.

"These incursions strengthen the hands of the militants, that is the result of this," said Talat Masood, a military and political analyst. "You don't want to strengthen them, you want to weaken them."

Pakistan has cited its offensive in the northwestern Bajur border region as an example of its commitment to rooting out extremists there.

Maj. Gen. Tariq Khan told reporters on an army-organized trip to the area Friday "that the consensus is that more than 1,000" militants had been killed since operations began in early August, including "seven or eight renowned Taliban commanders" as well as Arab and Uzbek fighters. He said 63 troops have died and 212 were wounded.

"My timeframe for Bajur is anything from between 1 1/2 to two months to bring about stability," Khan said.

Military officials paraded 10 blindfolded and handcuffed men said to be Taliban fighters arrested in the operation.

One said he was innocent, adding that he was picked up because he looked like a militant.

"I was on my way to my madrassah and ... they arrested me," said the man, who identified himself as Shah Khalid. "They didn't find any weapons with me, they just arrested me because of my hair."

The raid in Karachi targeted militants believed to be part of Lashkar-e-Jhangvi, an extremist group linked to al-Qaida. Police said a tip from a captured member of the group led security forces to the house.

The militants were suspected of planning an attack on a "high-profile" target in the city, said Sindh Police Chief Babar Khattak.

Officers seized at least 22 pounds of explosives, two suicide jackets, seven pistols and 12 grenades from the house.

Violence across Pakistan showed no sign of letting up following last weekend's truck bombing of the Hotel Marriott in Islamabad that killed 53 people.

Police raided a militant safehouse in Karachi, sparking a gunfight in which three extremists either blew themselves up or were shot.

A handcuffed man held captive and identified as a supplier of fuel and goods to U.S. and NATO forces in Afghanistan also died, said senior police official Aleem Jaffry.