The White House warned on Monday that Al Qaeda could launch a major attack on the United States in 2009, endorsing a similar warning by an independent senator Joe Lieberman.

The warnings coincide with media reports that top Bush administration officials drafted a secret plan late last year to enable US forces to operate inside Fata, but Washington turf battles and the diversion of resources to Iraq have held up the effort. At a White House briefing, press secretary Dana Perino did not confirm or deny the reports - saying that she could not "comment either way" - but she assured US citizens that the Bush administration had never allowed a "let up" in the search for Osama bin Laden and other Al Qaeda leaders.

Ms Perino, however, did not hesitate to confirm Mr Lieberman's fears. "Unfortunately, he could be right," she said. "We know there are people who are very dangerous and are trying to do that."

Mr Lieberman, who was a vice-presidential candidate in 2004, said in a television interview on Sunday that history shows the United States would likely face a terrorist attack in 2009.

"Our enemies will test the new president early," he said. "Remember that the truck bombing of the World Trade Centre happened in the first year of the Clinton administration. 9/11 happened in the first year of the Bush administration."

At the White House, Ms Perino noted that the people who were planning to attack the United States were "very dangerous and very secretive," and operated from "a very dangerous terrain, hiding in caves."

Explaining President Bush's strategy for dealing with this threat, she said the president was clear that "whenever we can we will take action" against such people. "We will not wait."

She said that people hiding in this "dangerous terrain" were "plotting to kill innocent people not just in the US but in other countries as well, even Muslims like in Iraq."

Mr Perino said that as part of its strategy to deal with this threat, the Bush administration was trying to help establish a better economic and political environment in Fata and elsewhere.

"So Senator Lieberman could be right but we are doing anything we can" to prevent a terrorist attack on the United States, she said.

President Bush, she said, was also doing all he could to ensure that Al Qaeda is routed out.