Pakistan denied it was expanding its nuclear arsenal, a week after the top U.S. military officer said there was evidence it was doing so.

Pakistan is battling a growing insurgency by Islamist militants with links to Al Qaeda and the Taliban. Washington is considering giving it billions of dollars in aid to help fight the insurgents, who are also blamed for attacks on U.S. and foreign troops in neighboring Afghanistan.

At a congressional panel last week, Adm. Mike Mullen, the chairman of the U.S. Joint Chiefs of Staff, was asked whether there was evidence that Pakistan was adding to its nuclear weapons systems and warheads. He simply replied: "Yes."

But Information Minister Qamar Zaman Kaira denied that assertion Monday.

"Pakistan does not need to expand its nuclear arsenal but we want to make it clear that we will maintain a minimum nuclear deterrence that is essential for our defense and stability," he said. "We will not make any compromise."

Pakistan, a desperately poor country of 170 million people, is thought to posses more than 60 nuclear weapons under a program that began when its traditional enemy, India, started producing them.

The advance of the Taliban has raised some concerns in the West that the weapons may one day fall into militant hands. A more likely scenario, analysts say, is that Islamists may infiltrate its nuclear facilities and get hold of nuclear knowledge and material.

"I want to tell the world in categoric terms that, with the blessing of God, Pakistan's nuclear assets are safe and will remain safe. No one, no matter how powerful and influential, eyeing on our national assets will succeed," Prime Minister Yousuf Raza Gilani said earlier, apparently referring to a common Pakistan belief that the United States wants to seize the country's weapons.

Pakistan is under intense international pressure to battle the insurgents. Last month it launched an offensive against between 4,000 and 5,000 militants in the Swat Valley area that the U.N. refugee agency says has so far driven nearly 1.5 million people from their homes. About 100,000 of them are now in sweltering refugee camps.

The offensive has so far enjoyed broad public support, but other military operations in the northwest, including one just last year in the Swat Valley, faltered amid criticism by lawmakers and the public, many of whom sympathize with the militant's pro-Islam and anti-American rhetoric.

On Monday, the government convened a meeting of political parties to bolster support for the current operation.

Legislators approved a resolution that urged them to "to make efforts to unite the nation in the face of the insurgency" in the Swat Valley, Kaira said. But the 16 point document did not contain language explicitly supporting the military offensive there.

The offensive was launched after the extremists failed to abide by a peace deal and advanced on the capital, generating anger and alarm among many Pakistanis. But analysts warn opinion could quickly turn against the operation if the fighting dragged on or if the refugees crisis was badly handled.

Pakistan says more than 1,000 militants have been killed so far, a claim that has been impossible to verify because journalists have largely been barred from the battle zone. It has not given any figures for civilian casualties, but refugees say they have occurred.

Army spokesman Maj. Gen. Athar Abbas said infantry troops were now moving into the main towns of the region after three weeks of mostly aerial bombardment of insurgent positions, camps and training grounds in the hills.

He said the army wanted a "quick and speedy operation so we can clear the area and allow the internally displaced people to return."