US President George W Bush on Sunday night said he would seek $87 billion more from Congress to finance the wars in Afghanistan and Iraq.

"This will take time and require sacrifice. Yet we will do whatever is necessary -- we will spend whatever is necessary -- to achieve this essential victory in the war on terror, to promote freedom, and to make our own nation more secure," Bush told Americans in a televised address.

He said the world has changed since the war began.

"For [the Iraqis], there will be no going back to the days of the dictator -- to the miseries and humiliation he inflicted on that good country," Bush said.

"For the Middle East and the world, there will be no going back to the days of fear -- when a brutal and aggressive tyrant possessed terrible weapons.

"And for America, there will be no going back to the era before September 11, 2001 -- to false comfort in a dangerous world."

The US will seek additional international help to rebuild Iraq, Bush said.

"I recognise that not all of our friends agreed with our decision to enforce the Security Council resolutions and remove Saddam Hussein from power. Yet we cannot let past differences interfere with present duties," he said.

United Nations members "have an opportunity and the responsibility to assume a broader role in assuring that Iraq becomes a free and democratic nation", he said.

He said the US strategy in Iraq has three objectives -- "destroying terrorists, enlisting the support of other nations for a free Iraq and helping Iraqis assume responsibility for their own defence and their own future".