US Vice-President Dick Cheney has made an unannounced visit to Iraq - his first since the 2003 US-led invasion.
Cheney has come under incessant criticism over the war
Mr Cheney praised Iraq's "tremendous" elections last week and was described by President Jalal Talabani as a "hero for liberating Iraq".
The visit was kept so secret that it is thought even the Iraqi prime minister was not told beforehand.
As one of the main advocates of the Iraq war, Mr Cheney has come under constant criticism by opponents.
The trip - Mr Cheney's first since 1991 when he was defence minister in George Bush senior's administration - came on the same day that President George W Bush was to give a prime-time address on Iraq.
The vice-president flew around the Baghdad area in a pack of eight fast-moving Blackhawk helicopters with guns mounted on the sides, the Associated Press news agency reports.
He had talks with Prime Minister Ibrahim Jaafari and Iraq's president before meeting US commanders.
Mr Cheney said the Iraqi participation in the elections was "remarkable".
"And that's exactly what needs to happen as you build a political structure in a self-governing Iraq that can unify the various segments of the population and ultimately take over responsibility for their own security," he told them.
"You've heard some prominent voices advocating a sudden withdrawal of our forces from Iraq," Mr Cheney told the servicemen, alluding to the Bush administration's critics.
"Some have suggested that the war is not winnable and a few seem almost eager to conclude the struggle is already over. But they are wrong. The only way to lose this fight is to quit and that is not an option."
More than 2,100 US troops have been killed in Iraq since the end of the US-led invasion of April 2003, alongside more than 30,000 Iraqis.
Last month, Democrat Congressman John Murtha caused a stir with his call for a pullout of US forces in Iraq - coming in the middle of a war of words over the issue.
Voting was deemed to have met standards
Mr Cheney responded by saying: "The suggestion that's been made by some US senators that the president of the United States or any member of this administration purposely misled the American people on pre-war intelligence is one of the most dishonest and reprehensible charges ever aired in this city.
"The president and I cannot prevent certain politicians from losing their memory, or their backbone - but we're not going to sit by and let them rewrite history.
Most recently the US vice-president has been accused of sanctioning the abuse of prisoners by US troops.
Mr Cheney left the US on Saturday for a five-day tour that includes Afghanistan, Pakistan, Egypt and Saudi Arabia.