President Obama addresses injured veterans at the Disabled American Veterans National Convention in Orlando, Florida, August 10, 2013. Obama spoke about making improvements to the speed in which a back log of veterans’ benefit claims are processed. (Brian Blanco/EPA)

President Obama on Saturday announced an initiative to help treat veterans with brain injuries and mental-health conditions, as he and first lady Michelle Obama paid tribute to disabled veterans before departing on their summer holiday.

Speaking to the annual conference of Disabled American Veterans, which represents 1.2 million people nationwide, Obama announced a $100 million grant to research centers, led by the University of Texas at San Antonio and Virginia Commonwealth University, dedicated to treating brain injuries and mental-health issues, particularly post-traumatic stress disorder.

He also said his administration would launch an effort to share research among the numerous federal agencies studying and providing treatment to veterans with neurological problems.

Brain injury and disease are among the enduring legacies of the wars in Iraq and Afghanistan, with significant numbers of veterans suffering post-traumatic stress disorder. In addition, the suicide rate among veterans has soared over the past decade.

“I’m not going to be satisfied until every veteran . . . gets the support and help they need to stay strong,” Obama told about 4,000 veterans gathered here. “We’ve got to end this epidemic of suicide among our veterans and troops.”

Obama addressed the group after his administration faced withering criticism from veterans’ advocates for the backlog of claims from disabled veterans, which stood at more than 600,000 in March. The backlog has been an embarrassment for a president who had pledged to promptly tend to the needs of veterans.

But Obama said Saturday that his administration has had success in reducing the backlog by more than 20 percent and is on track to eliminate it by 2015.

“I’m going to be honest with you: It has not moved as fast as I want it. That’s been unacceptable,” he said.

Obama blamed the delays on an influx of new veterans with post-traumatic stress disorder as well as new claims by veterans affected by Vietnam War-era Agent Orange.

“We are not where we need to be, but we’re making progress,” he said.

Obama became emotional as he discussed his four-year acquaintance with Cory Remsburg, a U.S. Army ranger who suffered a severe brain injury in Afghanistan and has slowly been on the mend.

“The war in Afghanistan may just be ending, but for Cory and our disabled veterans, the work has only just begun,” he said.

Obama also used his appearance in Orlando to discuss two policy and political challenges he is facing in Washington: the deep across-the-board spending cuts known as sequestration, which exempts the Department of Veterans Affairs, and challenges to his health-care law.

“Going forward, the best way to protect the VA care you have earned is to get rid of this sequester altogether,” Obama said. He also urged veterans not to be “hoodwinked” by those claiming that the Affordable Care Act will affect the care they receive from Veterans Affairs.

The first lady’s appearance before the group was notable because she and Jill Biden, the vice president’s wife, have forged the “Joining Forces” initiative to provide jobs to veterans by getting commitments from major U.S. corporations to hire them.

In her remarks, Michelle Obama recalled the emotional story of a retired Army sergeant who was badly wounded in his legs but finally walked again. Addressing the veterans, she said, “I see a group of people who know how to get back up.” She added: “You will never have to get back up all on your own. Not while we’re here.”

The president also extolled his efforts to help reduce unemployment among veterans and announced that his administration would work with community colleges and universities to provide veterans with support so they can complete higher education.

Obama’s appearance in Orlando was his second before a military community this week. He thanked about 3,000 Marines and sailors serving at Camp Pendleton, Calif., on Thursday as part of a West Coast tour.

The Obamas addressed the meeting before departing for an eight-day vacation in Martha’s Vineyard, Mass., where they have spent their summer holiday since first coming to office. (They skipped it last year during the presidential campaign.)

The vacation is shorter than usual, reflecting the domestic and foreign challenges the president faces. U.S. officials have been warning of a significant terrorist threat, one that led to the closing of 19 U.S. embassies and consulates across the Middle East and Africa over the past week. Eighteen were set to reopen Sunday.

Tensions, meanwhile, are escalating with Russia after former intelligence contractor Edward Snowden was granted a one-year asylum there. Obama canceled a summit with Russian President Vladimir Putin scheduled for next month.

At home, Obama is facing a growing controversy over surveillance, prompted by Snowden’s disclosures of National Security Agency programs to the media. At a White House news conference Friday, Obama said he would work with Congress to increase oversight of the Foreign Intelligence Surveillance Court, which approves government requests for warrants and other collection efforts, and other elements of the nation’s surveillance network.

While he is in Martha’s Vineyard, two big brewing domestic battles and a major economic decision will be on the president’s mind. Obama and Republicans are far apart on how to resolve a standoff over funding the government past a Sept. 30 deadline and on raising the federal debt limit, which will probably have to be done in October or November. Obama also is looking for ways to increase the odds of passing a bill overhauling immigration laws through the House.

In addition, the president is planning this fall to nominate a new Federal Reserve chairman, which he said would be one of his most important economic decisions.