WASHINGTON — President Obama declared an end on Tuesday to the seven-year American combat mission in Iraq, saying that the United States has met its responsibility to that country and that it is now time to turn to pressing problems at home.

In a prime-time address from the Oval Office, Mr. Obama balanced praise for the troops who fought and died in Iraq with his conviction that getting into the conflict had been a mistake in the first place. But he also used the moment to emphasize that he sees his primary job as addressing the weak economy and other domestic issues — and to make clear that he intends to begin disengaging from the war in Afghanistan next summer.

“We have sent our young men and women to make enormous sacrifices in Iraq, and spent vast resources abroad at a time of tight budgets at home,” Mr. Obama said. “Through this remarkable chapter in the history of the United States and Iraq, we have met our responsibility. Now, it’s time to turn the page.”

Seeking to temper partisan feelings over the war on a day when Republicans pointed out that Mr. Obama had opposed the troop surge generally credited with helping to bring Iraq a measure of stability, the president offered some praise for his predecessor, George W. Bush. Mr. Obama acknowledged their disagreement over Iraq but said that no one could doubt Mr. Bush’s “support for our troops, or his love of country and commitment to our security.”