US President Barack Obama plans to withdraw most of US troops out of Iraq in less than 19 months, pending a formal announcement later this week, officials said Tuesday.

Except a residual force between 30,000 to 50,000 to be left till December 2011, most of the 142,000 US troops will be out of Iraq by August 2010, 19 months after Obama's swearing-in on Jan. 20, US TV networks and wire services quoted administration officials as saying.

US President Barack Obama takes a question at the Fiscal Responsibility Summit at the White House in Washington February 23, 2009. [Xinhua]

Obama is meeting with Secretary of Defense Robert Gates at the White House Tuesday afternoon and he is expected to make a formal announcement later this week, probably on Wednesday, they said.

The new withdrawal timetable will be three months later than Obama's original pledge to pull out most troops in 16 months after his inauguration.

Some 4,250 US troops died and 650 billion US dollars have been spent since the United States invaded Iraq in March 2003.

(Xinhua News Agency February 25, 2009)