US President Barack Obama was to mark the formal end of the US combat role in Iraq with a visit Tuesday to a Texas military base and a major evening televised address, dpa reported.
Obama is expected to hail the transition to an Iraqi-led, civilian-led effort as a major milestone in the seven-year US war effort. White House officials said he will pledge that the handover will not end the US commitment to Iraq and its security.
Iraqis "will write the next chapter in Iraqi history, and they will principally be responsible for it," White House spokesman Robert Gibbs said Monday. "We will be their ally."
Vice President Joe Biden made a surprise visit Monday to Iraq to commemorate the transition and meet with political leaders, hoping to help break a deadlock that has existed between Iraq's main parties since the March 7 election.
The political infighting and a rise in violence in recent weeks has sparked concerns over the fate of Iraq as US combat forces leave the country.
US General Ray Odierno, who on Wednesday will hand over command of US forces in Iraq to Lieutenant General Lloyd Austin, said this week that the political crisis could erode trust in the democratic process.
"What I don't want is for them to lose faith in the system, the democratic system, and that's the long-term risk, do they lose faith in the process," Odierno told The New York Times.
Obama is scheduled to speak at 8 pm (0000 GMT Wednesday) from the Oval Office in the White House, after meeting earlier in the day with US Army troops at Fort Bliss, Texas.
Obama had set August 31 as the deadline for withdrawing combat forces, which was completed 11 days early, as part of his long- promised plan to shift focus to the conflict in Afghanistan.
Fewer than 50,000 troops remain in Iraq, as more than 94,000 US soldiers have left since Obama took office in January 2009.
The remaining troops are staying behind to continue training Iraqi security forces and assist in counterterrorism operations. They are due to leave by the end of 2011.
The State Department will be taking the lead from the US military on Wednesday. The new mission in Iraq will be called "New Dawn."