President Obama has been reminding the American public lately that he has kept his own promise to withdraw combat troops from Iraq by the end of August.

The White House has announced that Mr. Obama plans to cap things off with an August 31st prime time address to the nation from the Oval Office marking U.S. troops' shift there to a non-combat phase. But how different will the new mission be from the last?

"Today United States forces in Iraq announced that the United States now has less than 50,000 troops in Iraq," the President's Homeland Security and Counterterrorism Advisor John Brennan told reporters in Martha's Vineyard, where the president is vacationing.

"This reaches the goal that was set by the President last February as part of his efforts to responsibly draw down our forces from Iraq and transition to Iraqi security forces the responsibility for security in that country."

Indeed, the Iraqis will be charged with protecting themselves, but not everyone is sure they are ready. Additionally, the remaining U.S. troop contingent will be right behind the Iraqis, bolstering their security. So is the new phase Mr. Obama will tout all that different from the last?

Some reporters wonder aloud whether the war can technically be deemed "over" on September 1st. "Does the United States still consider itself at war in Iraq?" Brennan was asked.

He never fully answered, merely confirming the U.S. is still engaged in "military operations" there. "After September 1st, the United States will have a different mission, one of advising and assisting Iraqi security forces, joining the Iraqis in targeted counterterrorism operations and protecting U.S. troops and civilians who remain in Iraq," Brennan said.

However, the training of Iraqi forces is far from complete. Under a security agreement the Bush administration negotiated with the Iraqis, all of the U.S. troops are to be out of the country by the end of next year, save a small number to aid in the purchase of new American military equipment. Additionally, the State Department has been tasked to head up police training.

The challenge for Mr. Obama will be to convince the war-weary American public that September 1st is indeed a turning point.

Brennan acknowledges the mission may be changing but efforts to stabilize Iraq are far from complete. "We recognize that there's still more progress that needs to be made inside of Iraq to ensure that security is going to prevail throughout the country and is going to be enduring for many, many years to come."

Fox News Channel and its affiliates, as well as Fox Business Network will air the speech live. You can also stay tuned FoxNews.com for live streaming video of the speech.