WASHINGTON — The U.S. Veterans Affairs Department says it will look again at the rejected claims of veterans who say their Gulf War service caused a mysterious illness. It's the first step toward potentially compensating them nearly two decades after the war ended.

VA Secretary Eric Shinseki said the decision is part of a "fresh, bold look" his department is taking to help those veterans. The VA says it also plans to improve training for medical staff who work with Gulf War vets, so they don't simply tell vets that their symptoms are imaginary — as has happened to many over the years.

"I'm hoping they'll be enthused by the fact that this ... challenges all the assumptions that have been there for 20 years," Shinseki, a Kaua'i native and former Army chief of staff, said in an interview.

The changes reflect a significant shift in how the VA may ultimately care for some 700,000 veterans of the Gulf War. They also could improve the way the department handles war-related illnesses suffered by future veterans — Shinseki said he wants standards put in place that don't leave veterans waiting decades for answers to what ails them.

The decision comes four months after Shinseki opened the door for about 200,000 Vietnam veterans to receive service-related compensation for three illnesses stemming from exposure to the Agent Orange herbicide.

About 175,000 to 210,000 Gulf War veterans have come down with a pattern of symptoms ranging from mild to severe that include rashes, headaches, memory problems, joint and muscle pain, sleep issues and gastrointestinal problems, according to a 2008 congressionally mandated committee that based the estimate on earlier studies.

But what exactly caused the symptoms has long been unanswered. Independent scientists have pointed to pesticides and pyridostigmine bromide pills, given to protect troops from nerve agents, as probable culprits. The 2008 report noted that since 1994, $340 million has been spent on government research into the illness, but little has focused on treatments.

Steve Robertson, legislative director of the American Legion, a veterans' group, and a Gulf War veteran himself who has struggled with his own health issues, such as joint problems and chronic fatigue, said Friday the decision is welcome news.

"I can assure that there are Gulf War veterans who have been fighting this issue since 1991, '92," Robertson said. "The ones I've talked to are very, very upset that they've had to fight this battle."

James Bunker, president of the nonprofit National Gulf War Resource Center, also praised the decision but said he hopes the claims processors will be better trained so they don't reject the same claims again, turning the process into "something that had lifted the hopes of many veterans just to let them down again."

Last week, Shinseki and Sen. Jay Rockefeller, a Democrat on the Senate Veterans' Affairs committee, met privately with several Gulf War veterans. After the meeting, Rockefeller told the AP that Shinseki's background as a former Army chief of staff made the changes possible. He said the military has either been reluctant over the years to release paperwork related to the war or kept poor records about exposures in the war zone, which made it harder for the veterans to prove they needed help.

"The paperwork isn't very accurate, but the pain is very real," Rockefeller said.

A law enacted in 1994 allows the VA to pay compensation to Gulf War veterans with certain chronic disabilities from illnesses the VA could not diagnose. More than 3,400 Gulf War have qualified for those benefits, according to the VA.