President Obama speaks from Oval Office: “This completes a transition to Iraqi responsibility for their own security.”

Washington (CNN) — President Obama declared that “the American combat mission in Iraq has ended” in his primetime address Tuesday, according to excerpts released before the speech.

“Operation Iraqi Freedom is over, and the Iraqi people now have lead responsibility for the security of their country,” he said, according to the excerpts.

The president addressed the economic crisis in America by talking about how restoring prosperity at home is critical to maintaining the nation’s strength abroad. Obama said getting the economy back on track is his “central responsibility as president,” according to the excerpts.

“Today, our most urgent task is to restore our economy, and put the millions of Americans who have lost their jobs back to work,” the president said.

Obama said ending the war in Iraq is in the United States’ best interest and “now, it is time to turn the page.”

“Through this remarkable chapter in the history of the United States and Iraq, we have met our responsibility,” the excerpts said.

Obama also planned to ignore Republican suggestions that he acknowledge a personal mistake and give credit to former President George W. Bush for executing the 2007 troop surge, according to two senior administration officials familiar with the speech.

Obama, then a senator, and other Democratic senators at the time opposed the surge.

Senior administration officials said the president wanted his Iraq address to be more forward-looking and thus was not planning to spend any time in the 15- to 20-minute speech looking backward at the divisive 2007 congressional debate over whether Bush should surge more troops into Iraq.

Ignoring a replay of that 2007 debate could be politically advantageous for Obama, given the fact that top Republicans like House Minority Leader John Boehner earlier blasted the president for opposing the surge.

“One lawmaker rejected the idea that the surge would reduce violence in Iraq, saying — and again I’m quoting — ‘in fact, I think it will do the reverse,’” Boehner, R-Ohio, said in reference to Obama during a speech to the American Legion convention in Milwaukee.

GOP claims Iraq success despite Obama

Meanwhile, Senate Minority Leader Mitch McConnell, R-Kentucky, delivered a speech suggesting Bush deserves more credit for reaching this milestone.

“You might recall that the surge wasn’t very popular when it was announced,” McConnell said. “You might also recall that one of its biggest critics was the current president. So it makes it easier to talk about fulfilling a campaign promise to wind down our operations in Iraq when the previous administration signs the security agreement with Iraq to end our overall presence there.”

Asked about the Republican attacks on Obama, one senior administration official said flatly: “Who cares?”

This official explained the president was more interested in focusing on acknowledging the combat mission is coming to end and thanking U.S. troops for their hard work to “show the world America has the determination to finish the job” after a long conflict.

A second senior administration official added the president wanted to use the address in part to turn the nation’s attention to ratcheting up combat operations in Afghanistan. This official noted Obama spent a lot of time during the 2008 campaign vowing not only to bring home combat troops in Iraq within 16 months of taking office, but also said he wanted to finally give Afghanistan the resources it needed.

“This is what he promised in the campaign: responsibly ending the war in Iraq, and then using our resources to bring the fight directly to al Qaeda and the Taliban in Afghanistan,” said the senior official.

During a visit with U.S. troops at Fort Bliss, Texas, earlier on Tuesday, Obama signaled he would spend a good chunk of his speech preparing the nation for heavier casualties and “heartbreak” in Afghanistan in the days ahead as new commanding Gen. David Petraeus takes the fight directly to the enemy.

“We also have a very tough fight in Afghanistan,” Obama said. “It’s going to be a tough slog.”

Obama told the troops at Fort Bliss that his address will not be anything close to the “Mission Accomplished” moment his predecessor had.

“It is not going to be a victory lap,” Obama said. “We still have a lot of work to do.”

Fort Bliss has supplied soldiers to Iraq at all stages of the seven-year war and is still sending troops to the region as part of the 50,000-troop contingent that is staying in Iraq.

The president, who opposed the start of the war while he was serving as a state senator in Illinois, acknowledged there has long been debate about the merits of the conflict, but he said the focus now should be on the sacrifice of U.S. troops.

Al-Maliki marks U.S. end to Iraq combat mission in national address

“The one thing we don’t argue about is we have the finest fighting force in the history of the world,” Obama said. “America is more secure” because of their service.

Obama said the nation cannot forget about the war in Afghanistan, and it will be a heavy focus of Tuesday night’s speech, his second from the Oval Office. The first was about the Gulf oil disaster in early June.

Oval Office setting is message behind the message

“We also have a very tough fight in Afghanistan,” Obama said. “It’s going to be a tough slog.”

White House aides said Obama called Bush from aboard Air Force One on his way to Texas, but they declined to provide specifics about the call.

The August 31 drawdown and end to the U.S. combat phase is a new page in what has been a controversial seven-year conflict. Weapons of mass destruction, a major justification by the Bush administration for going to war, were never found. Saddam Hussein was toppled along with his massive Baghdad statue, but sectarian violence soon erupted.

The war in Iraq has so far claimed the lives of more than 4,400 U.S. troops.

CNN’s Dan Lothian contributed to this report.