The announcement probably comes as a disappointment to the U.S., which has pushed Pakistan to expand its military operations to target militants staging cross-border attacks against coalition troops inAfghanistan. Washington believes such action is critical to success in Afghanistan as it prepares to send an additional 30,000 troops to the country this year.

But the comments by army spokesman Maj. Gen. Athar Abbas clearly indicate Pakistan will not be pressured in the near term to expand its fight beyond militants waging war against the Pakistani state. Whether it can be convinced in the long term is still an open question.

"We are not talking years," Abbas told reporters traveling with Gates. "Six months to a year" would be needed before Pakistan could stabilize existing gains and expand any operations, he said.

The Pakistani army launched a major ground offensive against the Pakistani Taliban's main stronghold near the Afghan border in mid-October, triggering a wave of retaliatory violence across the country that has killed more than 600 people.

The United States wants Pakistan to take on militants who use its border region as a safe home base for attacks on U.S. forces in Afghanistan, but Gates said he will not directly press his hosts.

"I think the way I will approach it is simply to ask them what their plans are," Gates said, adding that the United States has heard of plans to expand Pakistani military operations against militants in the border area of North Waziristan sometime later this year. "I'd like to explore those with them."

Pakistan should be given room to expand its military offensive against militants on its own terms and timetable, Gates said ahead of his talks with the country's civilian and military leaders Thursday.

Referring to intense political pressure in Washington to lean harder on Pakistan, Gates sounded sanguine.

"As I try to remind Congress from time to time, and frankly some of the folks in the administration, it's the Pakistanis who have their foot on the accelerator, not us," Gates told reporters at the start of his two-day visit to Pakistan.

The political pressure goes two ways. Suspicion of U.S. motives runs high in Pakistan, and many Pakistanis bristle as the notion that Washington could dictate the country's priorities even with a recent promise of an unprecedented $1.5 billion in annual aid.

"We have to do this in a way that is comfortable for them, and at a pace that they can accommodate and is tolerable for them," Gates said. "Frankly, I'm comfortable doing that. I think having them set that pace as to what they think the political situation will bear is almost certainly the right thing to do."

Gen. David Petraeus, head of U.S. Central Command, said Thursday that U.S. aid must continue, along with the message that America is a "steadfast partner" when it comes to fighting terrorists.

"The challenge right now is there is a limit to (Pakistan's) capacity to put more short sticks into hornets' nests," Petraeus told an audience at the Center for Strategic and International Studies in Washington.

Gates said he is well aware of what he called conspiracy theories about U.S. motives in Pakistan, calling them "nonsense." He said the U.S. has no desire to take over control of Pakistan's nuclear weapons, occupy or split up the country, or divide the Muslim world.

He also said his talks with Pakistan's leaders were intended to explain the U.S. war strategy in Afghanistan and reassure Pakistan that the United States is "in this for the long haul."

But President Obama's comments in December that the U.S. would begin to withdraw its forces from Afghanistan in mid-2011 have raised questions among many Pakistani officials about Washington's commitment.

Gates cautioned Pakistan against trying to distinguish between the different militant groups in an essay published Thursday in The News, an English-language Pakistani newspaper.

"It is important to remember that the Pakistani Taliban operates in collusion with both the Taliban in Afghanistan and al-Qaeda, so it is impossible to separate these groups," Gates wrote.

"Only by pressuring all of these groups on both sides of the border will Afghanistan and Pakistan be able to rid themselves of this scourge for good — to destroy those who promote the use of terror here and abroad," Gates said.

One of the goals of his trip, he said, is "a broader strategic dialogue — on the link between Afghanistan' s stability and Pakistan's; stability in the broader region; the threat of extremism in Asia; efforts to reduce illicit drugs and their damaging global impact; and the importance of maritime security and cooperation. "

Gates' first meeting Thursday is with Defense Minister Ahmed Mukhtar. He also has separate meetings scheduled with Prime Minister Yousaf Reza Gilani and President Asif Ali Zardari.

Associated Press Writers Sebastian Abbot and Anne Flaherty contributed to this report.