US force levels will climb from 138,000 to about 150,000 by early January, extending tours of duty and deploying fresh troops from the United States, said US Brigadier General David Rodriguez.

That was the number of US ground troops in Iraq at the end of major combat operations April 30, 2003.

"The purpose is mainly to provide security for the elections, but it is also to keep up the pressure on the insurgents following the Fallujah operation," Rodriguez said.

The top US commander in Iraq, General George Casey, is extending the deployment of units already in Iraq to keep experienced forces during the period, Rodriguez said.

Two battalions of the 82nd Airborne Division have also been ordered to deploy to Iraq for 120 days.

Meanwhile, Iraqi interim Prime Minister Iyad Allawi was in Jordan, where he met King Abdullah II and Iraqi exiles to rally support for the planned January elections.

Imad Shabib, a member of Allawi's Iraqi National Accord party, said the talks sought to "forge unity in Iraq away from confessional differences" in the run-up to the polls.

Jordan will "fully support" Baghdad in its efforts to hold elections, state television quoted King Abdullah as saying.