VINEYARD HAVEN, Mass. - President Barack Obama said the withdrawal of U.S. combat troops from Iraq means "the war is ending" and Baghdad is in position "to chart its own course."

Obama used his weekly radio and Internet address Saturday to highlight Tuesday's formal end to U.S. combat missions in Iraq and remind people that he's keeping a promise he made as a candidate in the 2008 election.

Remaining troops will assume a backup and training role, a shift Obama will underscore with a visit to Fort Bliss, Texas, on Tuesday and then a prime-time speech to the nation from the Oval Office. The events come on Aug. 31, the date he set last year for the change in focus in the war.

U.S. troop strength dropped below 50,000 this past week, a milestone also highlighted by the administration.

"In the months ahead, our troops will continue to support and train Iraqi forces, partner with Iraqis in counterterrorism missions and protect our civilian and military efforts," Obama said, a day before ending his 10-day Martha's Vineyard vacation to travel to New Orleans and mark another somber date: the fifth anniversary of Hurricane Katrina.

Driving home his point, the president said, "The bottom line is this: The war is ending. Like any sovereign, independent nation, Iraq is free to chart its own course. And by the end of next year, all of our troops will be home."

Senate Republican leader Mitch McConnell of Kentucky said while "much hard work remains" in Iraq, "U.S. combat forces in Iraq have done everything their country asked of them over the past seven years. We owe them our deepest gratitude for all they have done, are doing, and will continue to do in defense of our nation."

The end to U.S. combat action in Iraq falls short of the "mission accomplished" moment that bedeviled former President George W. Bush, given the continuing violence and political instability in Iraq and the ongoing commitment of remaining U.S. troops. But Obama seized on it as an opportunity to show he's making good on a promise that was a driving force for his presidential campaign, before his term in the White House was overtaken by economic issues.

"As a candidate for this office, I pledged I would end this war. As president, that is what I am doing," Obama said. "We have brought home more than 90,000 troops since I took office. We have closed or turned over to Iraq hundreds of bases. In many parts of the country, Iraqis have already taken the lead for security."

Obama also pledged continued support for veterans and the Veterans Affairs Department, noting that the Iraq and Afghanistan wars produce different injuries than past conflicts.

"Too many suffer from traumatic brain injury and post-traumatic stress disorder - the signature injuries of today's wars - and too few receive proper screening or care. We're changing that," Obama said, calling it a "moral obligation."

The weekly Republican address focused on the economy and government spending, with the party's Florida Senate candidate, Marco Rubio, taking on the Democrats who run the show in the capital.