US Defence Secretary nominee Robert Gates has told a Senate committee that the US is not winning the war in Iraq.
Mr Gates told a confirmation hearing he was open to new ideas on Iraq, but warned the situation there would shape the Middle East for years to come.
The committee approved him to replace Donald Rumsfeld, who quit last month amid criticism of his Iraq policy.
The next chairman of the panel said Mr Gates would face a monumental challenge if confirmed by a full Senate vote.
After the 21 senators on the committee unanimously approved Mr Gates, the Senate should vote by the end of the week, with approval widely expected.
Senate hearings on Mr Gates' nomination began a day before the Iraq Study Group - of which Mr Gates was a member - publishes its findings.
The session also came on another violent day in Iraq.
More than 30 people were killed in shootings and car bomb attacks in Baghdad, Iraqi officials said. At least 30 more died in violence in northern and south-western Iraq.
Mr Gates told the Senate Armed Services Committee that all options remained on the table for Iraq.
He agreed with the panel that the situation was unacceptable and said he would introduce a change of tactics, if confirmed.
Mr Gates said he would do his utmost to avoid chaos in Iraq.
"Our course over the next year or two will determine whether the American and Iraqi people and the next president of the US will face a slowly but steadily improving situation in Iraq or... the very real risk and possible reality of a regional conflagration," he said.
Asked by the next chairman of the panel, Democratic Senator Carl Levin, if he believed the US was winning, Mr Gates replied: "No, Sir."
He later said he believed the US was neither winning nor losing, "at this point".
Mr Levin said the US needed someone who would speak the truth, and not just tell the president what he wanted to hear.
Mr Gates said the president would have the last say on any changes in approach, but he would speak his mind to both Mr Bush and Congress.
"I did not want this job," he reminded the senators.
"I'm doing it because I love my country."
In wide-ranging remarks, the nominee also:
- Said the US should attack Iran only as a last resort and he would not support military action against Syria
- Called for a broad bipartisan agreement on how to fight war on terror
Now that the panel has approved his nomination, the 63-year-old is likely to appear before the full Senate for a confirmation hearing later this week.
Democratic senators are thought unlikely to oppose Mr Gates' nomination not least because they are keen to see Mr Rumsfeld leave the role quickly.
Mr Gates met Mr Bush for breakfast at the White House before the hearing, after which the president said the nominee would "do an excellent job".
Correspondents say he would probably be the most significant new blood to come into the Bush team since the president took office.
Mr Gates stood down from the bipartisan Iraq Study Group - which has been asked to recommend ways of tackling the problems the US faces in Iraq - after Mr Bush picked him to replace Mr Rumsfeld.
The group's recommendations are widely expected to include a gradual phased withdrawal of US troops over the next 18 months.
It is also thought to favour the idea of holding a regional conference on Iraq that would involve Syria and Iran, with whom Washington has refused to negotiate directly.
Mr Bush has indicated he will look closely at, but not necessarily follow, the group's suggestions.