In an interview with Reuters on Monday that ranged across world hot spots from Iran to North Korea and touched on her legacy, Rice said she was not worried about how she would be perceived and dismissed the view of leading Democrats and a majority of Americans that invading Iraq was a mistake.

"I am proud that we overthrew Saddam Hussein," she said. "I don't consider it an issue of legacy, I consider it an issue of having done the right thing."

Tens of thousands of Iraqi civilians have died and nearly 3,800 US troops have been killed since the March 2003 US-led invasion that toppled Saddam Hussein and unleashed a vicious insurgency and mass sectarian violence.

With 14 months until the next US Presidential election, the Bush administration is under growing pressure to bring home some of the roughly 169,000 troops in Iraq as the costs of the war, now in its fifth year, mount.

The White House has already spent more than $421 billion on the war, according to the Congressional Budget Office, and may ask for as much as $200 billion more for the next fiscal year.

"I am not worrying about my legacy. With 14 months to go, I am worrying about what we get achieved," she said.

Rice was national security adviser to US President George W Bush when he made the decision to invade Iraq. She moved to take over the US State Department in 2005, where she has had a tough time grappling with how to stabilize Iraq.

'Historical Changes'

Rice said the Bush administration had made a lot of difficult, historical decisions since 2001 -- after the Sept 11 attacks forever altered Bush's Presidency -- and that ultimately these may be viewed more favorably.

"Big, historical changes take time to play out. I am quite confident that today's headlines and history's judgment are rarely the same," she said. "For me, the issue is: What do we do to help put Iraq into a sustainable position from a point of view of American policy?"

There is considerable skepticism among Americans about the US involvement in Iraq and anti-war sentiment helped the Democrats win both houses of Congress from Bush's Republicans last year.

A Gallup poll taken earlier this month showed a majority of Americans -- 58 per cent -- believe the United States made a mistake in sending troops to Iraq.

In a new book about Rice, Washington Post diplomatic correspondent Glenn Kessler suggested she had spent much of her time as secretary of state trying to rectify mistakes made when she was national security adviser.

Asked about the criticism, Rice bristled and said she believed the opposite was true.

"Actually, I think I am reaping the benefits of decisions that were made when I was national security adviser. That is, I think, the way history often turns out," she said.

Whatever happens in Iraq, Rice -- like Bush -- suggested America was likely to be there for a long time and that this would be key to stabilizing the Middle East in general.