Welcoming veterans to his home on Memorial Day, Vice President Joe Biden told them this morning that the U.S. is "behind" in caring for its soldiers and that problems at the Veterans Affairs Administration must be addressed.

"That is a sacred obligation, and we're behind right now," Biden said. "The VA is having problems, and we've got to get to the bottom of it."

Biden referenced recent expansions of VA eligibility, such as the Obama administration's move in 2010 to change VA rules and pay new claims to vets who were exposed to the Agent Orange herbicide used by the U.S. military in Vietnam, but he said that's no reason for other failures to be tolerated.

"This is a long-term commitment this nation has to make, so it seems to me on this day we as Americans have to recommit ourselves not just with words but with deeds," Biden said.

It was a brief reference to the simmering VA scandal at an otherwise bittersweet and happy event: The VP and his wife, Dr. Jill Biden, welcomed a group of vets to their home at the U.S. Naval Observatory in northwest D.C. to kick off the sixth annual Ride 2 Recovery Memorial Challenge, a six-day, 350-mile bike ride from the Bidens' home to Virginia Beach. The group encourages vets to ride as a means to adjust to civilian life and to recover from post traumatic stress disorder. Many of the participants suffer from severe forms of it, a spokeswoman said.

The VA has come under intense scrutiny after allegations that VA hospitals covered up how long veterans were waiting to receive care - and that some veterans died while waiting to get it. The VA's inspector general is investigating 26 hospitals, and some have called for the resignation of VA Secretary Eric Shinseki.

The vice president and Dr. Jill Biden thanked the veterans for serving and praised them for courage in recovery. The VP joked and snapped selfies with the vets in attendance.

After the Bidens' remarks, riders departed for their six-day ride. Pedaling past a small cluster of TV cameras on his way out of the Bidens' driveway, one rider shouted, "Fix the VA!"