Washington, Feb 7: The Obama Administration is weighing three different military options for withdrawing troops from Iraq, including the possibility of breaking Barcak Obama's campaign pledge of a pullout within 16 months, a senior US official has said.

One of the options is along the lines of Obama'''s campaign pledge of 16 months, and the Joint Chiefs of Staff have drawn up what that would entail, FOX News reported.

The second option envisions about 23 months for combat forces to leave, an option that many of the military leaders favor because it would not require leaving so much equipment behind.

It also could be done in a more orderly manner, and bases could be cleaned up and closed properly, the US said.

A third, in-between option of 19 months, is also being weighed. One of the officials said that the main focus appears to be on the 16-month and 23-month options; 23 months would run to the end of 2010.

Obama's top two defense advisers, Defense Secretary Robert Gates and Joint Chiefs Chairman Adm. Mike Mullen, have not yet provided a formal recommendation to the president on a timetable, an official said. (ANI)