Trying to rally support for an unpopular war, President George W Bush used declassified intelligence on Wednesday to equate the US-led fight in Iraq with the broader battle against al Qaeda.
Speaking at a US Coast Guard Academy commencement ceremony, Bush cited newly released information asserting that Osama bin Laden had enlisted al Qaeda operatives in Iraq in 2005 to plot attacks on US targets.
Bush said it showed the need for US resolve in Iraq to keep it from becoming a staging ground for new strikes on American soil, an argument he has put forth repeatedly as the war has grown increasingly unpopular at home.
"Al Qaeda is public enemy number one in Iraq's young democracy. Al Qaeda is public enemy number one for America as well," Bush told a crowd of more than 5,000 people on the banks of the Thames River in New London, Connecticut.
Bush aides denied any political motives in his declassification of 2-year-old intelligence as he battled congressional Democrats opposed to his war policy.
The administration has been accused of selectively releasing sensitive information to bolster its case in Iraq.
Mindful of his trouble selling the US public on the war, Bush has stepped up efforts to put the spotlight on al Qaeda, the Islamist group behind the September 11 attacks on the United States.
Bush's critics say he is trying to de-emphasize the role of sectarian fighting in Iraq's chaos and justify the US military presence there by focusing on ties to al Qaeda and bin Laden, who has eluded a US-led manhunt. They say Iraq is a distraction from a more important war in Afghanistan.
The White House said the intelligence declassified on Tuesday provided further evidence of bin Laden's connections to Abu Musab al-Zarqawi, head of Iraq's al Qaeda wing, who was killed in a US air strike in June 2006.
Bush said bin Laden had ordered Zarqawi in January 2005 to form a cell to conduct attacks outside of Iraq and to make America his "number one priority."
The administration has abandoned earlier charges that al Qaeda had ties to the government of Iraqi leader Saddam Hussein before he was toppled in a 2003 US-led invasion.
The declassification came as the Democratic-led US Congress prepared to approve funding for the war, which polls show a majority of Americans oppose.
Democrats and the White House had battled fiercely over the money since January when Bush asked for nearly $US100 billion ($NZ137 billion) for the wars in Iraq and Afghanistan.
The House of Representatives is expected to vote first on Thursday, before sending the bill to the Senate for final passage of the measure that will bring total war spending to more than half a trillion dollars since late 2001.
In his address to graduating ensigns, Bush recounted a series of other al Qaeda plots against the United States he said US intelligence had foiled since the September 11 attacks.
"If we fail in Iraq, the enemy will follow us home," Bush said. Al Qaeda has been behind some of the bloodiest attacks in Iraq in the past four years.
Fran Townsend, Bush's homeland security adviser, said the intelligence on the Zarqawi-bin Laden connection was declassified because all leads had been exhausted.