ORLANDO, Fla. » President Barack Obama assured disabled veterans today that his administration is making progress on reducing a backlog of disability claims and said the number of requests for assistance has fallen by nearly one-fifth since peaking at more than 600,000 just a few months ago.

In an address at the Disabled American Veterans’ convention in Orlando, Obama also announced a national plan to guide mental health research, as well as commitments from 250 community colleges and universities to help veterans earn college degrees or get the credentials they need to find jobs.

A chief concern for veterans is the backlog of disability claims for compensation for illness and injury caused by military service.

"After years of military service, you shouldn’t have to wait years for the benefits you’ve earned," Obama said.

The number of claims ballooned after Obama made it easier for Vietnam veterans who were exposed to the herbicide Agent Orange to get benefits. Access to benefits also was eased for sufferers of post-traumatic stress disorder and Gulf War veterans afflicted with malaria, West Nile virus or other infectious diseases.

The backlog is shrinking due to some aggressive steps taken by the Department of Veterans Affairs, including requiring claims processors in its 56 regional benefits offices to work overtime and moving from a manual to a computerized system to help speed the judgment of claims, administration officials said.

About 780,000 claims are pending. About 496,000 are considered backlogged after the 20 percent reduction Obama highlighted, down from 611,000 at the end of March, said White House press secretary Jay Carney. A claim is considered backlogged if it has been in the system for 125 days, or roughly four months.

Even with that progress, Obama acknowledged the amount of work still needed to eliminate the backup by 2015 as VA Secretary Eric Shinseki has promised.

"Today I can report that we are not where we need to be, but we are making progress," Obama said. "So after years when the backlog kept growing, finally the backlog is shrinking."

The president also announced the release of a comprehensive national plan to improve the ability to prevent, diagnose and treat PTSD and traumatic brain injuries and mental health issues earlier and better, and to reduce suicides, according to a briefing paper the White House released today before the president spoke.

Beyond the claims issue, Republican lawmakers have started to hammer the VA on the issue of patient safety.

A congressional hearing in Atlanta this past week focused on poor patient care linked to four deaths. Another hearing is scheduled for next month in Pittsburgh, where five veterans died as a result of a Legionnaire’s disease outbreak in 2011-12.

Several dozen protesters greeted Obama as he arrived at the hotel. Some held signs that said "Kenyan Go Home," ”Impeach Obama," and "Obama Lies."

Obama met privately with DAV members before the speech, the White House said. Afterward, he headed to Martha’s Vineyard, Mass., for a family vacation.

Associated Press writer Kevin Freking contributed to this report.