British Prime Minister Tony Blair dismissed this mounting calls to set a timetable for the withdrawal of British troops from Iraq, saying they would remain until local forces could maintain security.
Escalating violence and the rising number of British deaths in Iraq, nearing 100, has fuelled criticism that Blair has no clear strategy for bringing soldiers home after the 2003 war, which was deeply unpopular in Britain.
Last week's storming of a police station by British soldiers in the southern city of Basra, to free two undercover soldiers detained by Iraqi police, has also sparked concern.
"The strategy has always been we retire as the Iraqi capability builds up," he told BBC television in an interview at the start of his centre-left Labour Party's annual conference.
"The timescale is -- when the job is done."
Mr Blair, who said he had not expected such fierce disruption to Iraq's fledgling political process from insurgents, did not explicitly deny a report in Sunday's Observernewspaper that a pullout plan was in circulation.
He did say, however, that he was not aware of a detailed plan for withdrawal to start next May, as stated by the newspaper.
"I think what people may be thinking of is what we've been working on with the Iraqi government for some time, which is, as Iraqi forces build up, what is then the future needs for the multinational forces' contribution?" said Mr Blair.
"The fact is -- what we do depends on the job being done. No arbitrary date on the job has been set," he said, adding that the UN mandate was to stay as long as the Iraqi government wanted.
Mr Blair's trust ratings slumped after the Iraq war and the issue will dog him through this week's conference. A YouGov poll for Britain's Five News had 57 per cent of respondents saying British troops should pull out of Iraq.
Britain's withdrawal also depends on Washington.
Public support for President George W. Bush's Iraq policy has eroded in the past year as the US military death toll increases towards 2,000.
Mr Blair also insisted the invasion of Iraq was crucial for British and world security.