British Prime Minister Tony Blair has told a joint session of the United States Congress that history would forgive them even if no weapons of mass destruction were found in Iraq.

"If we are wrong, we will have destroyed a threat that at its least is responsible for inhuman carnage and suffering. That is something I am confident history will forgive," Blair said during his 40-minute address on Thursday.

"But if our critics are wrong... and we do not act, then we will have hesitated in the face of this menace when we should have given leadership. That is something history will not forgive.

"We promised Iraq a democratic government. We will deliver it. We will stay with these people still in need of our help till the job is done," he said.

Blair urged the US to confront terrorism and tyranny with values, not just guns.

"America must listen as well as lead -- but don't ever apologise for your values," he said.

"What you bequeath to this anxious world is the light of liberty."

Blair said that from Kashmir to West Asia, Chechnya, Indonesia and Africa, barely a continent or nation was unscathed by terrorism.

He said the United Nations must play a central role in stemming the spread of WMDs. He also urged for a 'reform of the Security Council' and a new international regime on non-proliferation and WMDs.

"And we need to say clearly to UN members: If you engage in systematic and gross abuse of human rights, in defiance of the UN Charter, you cannot expect to enjoy the same privileges as those who conform to it," the British PM said.

The congressmen welcomed Blair's speech with wide applause.

Blair's visit to US came amidst heavy criticism at home for the failure of the victors of the war to find WMDs and the controversy over claims that Saddam Hussein was seeking nuclear material from Niger.

After his speech, Blair joined President George W Bush in an afternoon press meet to deny that they manipulated the intelligence on Iraq.

"I take responsibility for making the decision, the tough decision, to put together a coalition to remove Saddam Hussein," Bush said.

"The intelligence -- not only our intelligence but the intelligence of this great country (UK) -- made a clear and compelling case that Saddam Hussein was a threat to security and peace," Bush said.

"The British intelligence that we had, we believe, is genuine," Blair said. 'We know for sure that Saddam purchased some 270 tonnes of nuclear material from Niger' in 1980s, he added.

"Our enemies," said Bush, "are looking for signs of hesitation. They are looking for weakness. They will find none. Instead, our forces in Iraq are finding these killers and bringing them to justice."

Press Trust of India