"We remain ready, willing and able to assist the Pakistanis and to partner with them to provide additional training, to conduct joint operations, should they desire to do so," Gates told a news conference.
Gates said the Pakistani government has not requested any additional assistance in the weeks since al Qaeda and affiliated extremists have intensified their fighting inside Pakistan. And he stressed that the United States would respect the Pakistanis' judgment on the utility of American military assistance.
"We're not aware of any proposals that the Pakistanis have made to us at this point," he said. "This is clearly an evolving issue. And what we have tried to communicate to the Pakistanis and essentially what we are saying here is we are prepared to look at a range of cooperation with them in a number of different areas, but at this point it's their nickel, and we await proposals or suggestions from them."
Gates made his remarks not as an announcement but in response to questions from reporters at a regularly scheduled news conference in which he also declined to say whether U.S. combat troops have previously crossed the border from Afghanistan into Pakistan to conduct combat operations.
The question of a U.S. troop presence in Pakistan is highly sensitive, although at times senior U.S. officials have acknowledged various arrangements. In an Associated Press interview in January 2002, for example, Gen. Tommy Franks, who headed the U.S. Central Command at the time, disclosed a deal with Pakistan allowing U.S. troops in Afghanistan to cross the border in pursuit of fugitive extremist leaders.
Gates said Pakistani authorities were understandably taking their time in deciding whether to request more military assistance from the United States. He noted the assassination in Dec. 27 of former prime minister and opposition leader Benazir Bhutto and subsequent fears of increased unrest.
"I think that the emergence of this fairly considerable security challenge in Pakistan has really been brought home to the Pakistani government relatively recently and particularly with the tragic assassination of Mrs. Bhutto," Gates said. "So I think it's not particularly surprising that they have not fully thought through exactly how they intend to proceed and their strategy going forward."
The United States has about 28,000 troops in neighboring Afghanistan, and Gates earlier this month ordered another 3,200 to go this spring to train Afghan forces and to help fight Taliban insurgents.
U.S. intelligence believes al Qaeda leader Osama bin Laden is on the Pakistani side of the border with Afghanistan.
The top American commander in the region, Navy Adm. William J. Fallon, was in Pakistan earlier this week meeting with senior Pakistani officials, including the new army chief, Gen. Ashfaq Kayani. Last week Fallon told reporters that Pakistani officials were more willing to seek U.S. assistance.
Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, who appeared at the news conference with Gates, said he did not know whether Fallon had offered or received any new proposals.
Most of the discussion with the Pakistanis thus far has focused on the possibility of U.S. troops being used to train Pakistani forces, Gates said, but he acknowledged that combat operations might also be included.
"You're not talking about significant numbers of U.S. troops for the kinds of things if you're talking about going after al Qaeda in the border area or something like that," Gates said. "So, in my way of thinking, we're talking about a very small number of troops, should that happen. And it's clearly a pretty remote area. But, again, the Pakistani government has to be the judge of this."
Asked more specifically what he meant by a "very small number" of U.S. troops, Gates declined to comment.
Mullen said talks with the Pakistanis are progressing and that the U.S. military stands ready to provide training or combat forces.
"If asked to assist, I think we could do a lot," Mullen said.
For several years the focus of U.S. concern about al Qaeda elements in Pakistan was their support for Taliban extremists who have received training in western Pakistan and then infiltrated into Afghanistan to foment violence. More recently, al Qaeda in Pakistan has posed more of a threat to the Pakistani government, seeking to destabilize the government of a nuclear-armed Muslim nation.
At his news conference, Gates said the concern about al Qaeda goes beyond its threat to Pakistan and Afghanistan.
"We are all concerned about the reestablishment of al Qaeda safe havens in the border area," he said. "I think it would be unrealistic to assume that all of the planning that they're doing is focused strictly on Pakistan. So I think that that is a continuing threat to Europe as well as to us."