British Defence Secretary Geoff Hoon has confirmed that the US has asked for British troops to provide assistance outside the UK-controlled southern sector of Iraq.
But he insisted that no decision had yet been made in response. A final recommendation from the Chief of Defence Staff is expected by the middle of the week.
Mr Hoon assured MPs in a Commons statement that the request did not ask for troops to be deployed to Baghdad city or Fallujah.
He denied the request was political and had anything to do with the timing of the US presidential election.
It is thought the Americans have asked for a UK force of about 650 to move into an area south of Baghdad, where a US unit has been earmarked for combat operations in the insurgent stronghold of Fallujah.
Opposition leaders have expressed concern about British troops coming under American command.
Deadline for handover extended
In a separate development, the interim Iraqi government has extended its deadline for weapons to be handed in by supporters of Moqtada al-Sadr.
Militants will have another five days to exchange their heavy weapons for cash as part of a deal to end clashes between militants and US forces.
