President George W Bush was to press his case for the unpopular US mission in Iraq on Wednesday by offering new evidence that Al-Qaeda wants to turn it into a "sanctuary" to plot attacks on America.
Bush was expected to present newly declassified intelligence charging that Al-Qaeda chief Osama bin Laden told the group's late leader in Iraq, Abu Musab al-Zarqawi, to plan terror strikes on the United States.
Frances Townsend, Bush's homeland security advisor, made the revelation on Tuesday in defense of Washington's argument that it is fighting in Iraq to prevent the country from becoming a new "sanctuary" for Al-Qaeda.
The bin Laden-Zarqawi link was made in secret documents that were declassified on Tuesday, amid pressure from Democratic lawmakers for US troops to begin withdrawing from Iraq.
"The intelligence community tells us that in January of '05 (2005) bin Laden tasked Zarqawi, who has been in Iraq, to form a cell to conduct attacks outside Iraq, and then frankly America should be his number one priority," she said.
"We know from the intelligence community that Zarqawi welcomed the tasking and claimed he had already had some good proposals," Townsend said.
Later that spring, bin Laden ordered Al-Qaeda's operations chief, Hamza Rabia, to go to Iraq to brief Zarqawi about his plans for terror strikes, including in the United States, she said.
At that time, a top Al-Qaeda member, Abu Faraj al-Libi, also suggested to bin Laden that he send Rabia to Iraq help Zarqawi plan external operations.
Rabia was killed in Pakistan in December 2005. Zarqawi was killed on June 7, 2006 in an US air raid on Baquba, north of Baghdad. Libi was captured in May 2005 and is being held at the US naval base in Guantanamo Bay, Cuba.
The information comes as the White House faces opinion polls showing a majority of Americans want US troops to be pulled out of Iraq, more than four years after the US-led invasion that ousted Saddam Hussein.
For the past several weeks, Bush has made the fight against Al-Qaeda one of his chief arguments to defend the war.
Townsend said Bush would cite the intelligence on the bin Laden-Zarqawi link in a speech to the Coast Guard Academy on Wednesday in New London, Connecticut.
"The president will sort of confront the question about why does bin Laden really care in Iraq," she said.
"What he (bin Laden) wants is a terrorist sanctuary from which he can expand his influence and plot attacks, including against us here at home," she said.
She compared the threat to Al-Qaeda's alliance with the Taliban regime that allowed the terrorist network to set up camp in Afghanistan until the United States invaded the country following the September 11, 2001, attacks.
"You saw in Afghanistan that if they find sanctuary or safe haven, they will take advantage of it not only to extend their influence but to plot attacks against us," Townsend said.
"The lesson of September 11 is: don't permit them to find sanctuary or safe haven and constantly keep them running from us so that we don't have to face them here," she said.
The White House pre-emptively defended its timing of the new intelligence's release amid a political brawl with Democrats over lawmakers' attempts to set a timeline for the withdrawal of US troops.
"It takes time ... to put those pieces of the puzzle together," Townsend said.
The new information, however, raises new questions over the duration of the US military presence in Iraq.
Bush often insists that US patience in Iraq is not unlimited.
But Gordon Johndroe, a White House spokesman, said the information revealed in the intelligence made public on Tuesday "is part of the reason why the president is opposed to (withdrawal) timelines."