President Barack Obama declared an end to the seven-year U.S. combat mission in Iraq on Tuesday and told war-weary Americans his central responsibility now is to restore the sagging U.S. economy.

Now, it is time to turn the page, Obama said in an Oval Office address, speaking from the same desk former President George W. Bush had used to declare the 2003 start of the war.

Obama, who inherited the war from Bush and is fighting another in Afghanistan, said he had fulfilled a 2008 campaign promise to end U.S. combat operations in Iraq and that the Iraqi people now have lead responsibility for the security of their country.

Iraqi Prime Minister Nuri al-Maliki told Iraqis their country today is sovereign and independent but many are apprehensive as U.S. military might is scaled down, especially in the midst of continuing violence and a stalemate in efforts to form a new government six months after an inconclusive election.

Almost a trillion dollars (652 billion pounds) have been spent and more than 4,400 U.S. soldiers and at least 100,000 Iraqi civilians have been killed since the 2003 invasion. A recent CBS News poll found 72 percent of Americans now believe the war was not worth the loss of American lives.

The impasse in Iraq has raised tensions as politicians squabble over power and insurgents carry out attacks aimed at undermining faith in domestic security forces.

Tonight, I encourage Iraq's leaders to move forward with a sense of urgency to form an inclusive government that is just, representative, and accountable to the Iraqi people, Obama said.

The president, who opposed the war from the start, said he spoke to Bush earlier in the day by phone. He stopped short of praising Bush, as Republicans have demanded, for launching a 2007 troop surge that helped turn the tide in the war.

It's well known that he and I disagreed about the war from its outset. Yet no one could doubt President Bush's support for our troops, or his love of country and commitment to our security, Obama said.

(Additional reporting by Ross Colvin, Patricia Zengerle, Alister Bull and Caren Bohan; Editing by David Alexander)