Amid persistent complaints about veterans’ health care, President Barack Obama acknowledged lingering weaknesses Friday in the federal government’s response to the chronic delays and false waiting lists that triggered a national outcry over the Veterans Affairs health system last year.

Obama said that while VA Secretary Robert McDonald is “chipping away” at the problem, it was clear there was still more work to do.

“It’s important that veterans know that somebody’s got their backs, and that if there are problems that we’re not being defensive about it, not hiding it,” Obama said.

In his first trip to the Phoenix VA hospital whose practices sparked the scandal, Obama announced the creation of an advisory committee to recommend further steps the VA could take to improve veterans’ access to health care.

Obama met with veterans, VA employees and elected officials, including John McCain and Jeff Flake, Arizona’s two Republican senators. He said lawmakers specifically raised questions about the slow pace of implementing a new law meant to increase health care choices for veterans. Mental health and suicide prevention are also areas of concern, he said.

“Trust is something you can lose real quick,” Obama said, promoting the need to restore trust and confidence in the VA system. But, he added, “Every veteran I talked to today said that the actual care they received once in the system was outstanding.”

Obama’s visit came amid questions from lawmakers who say veterans are still not benefiting from changes in the law that were meant to improve their access to care. A month ago, Obama drew criticism for traveling to Phoenix without stopping at the VA hospital.

McCain, chairman of the Senate Armed Services Committee, blasted the president’s visit Friday as a “photo op.” He said the foot-dragging in implementing VA reforms showed that Obama’s administration had given up on reform before it even started.

“The American people — and veterans in particular — should be as unimpressed by the president’s high-profile but empty gesture today as I am,” said McCain, who scheduled a news conference outside the VA to respond on camera to the president’s visit.

As Obama flew to Phoenix, the White House defended the VA’s actions to correct problems.

“Long after it fades from the headlines, this is something a lot of people have been working on and that he president feels strongly about,” White House spokesman Eric Schultz said.

Aiming to illustrate a more positive veteran’s story, Obama also paid a visit to Sgt. 1st Class Cory Remsburg, who was wounded in Afghanistan and has met with Obama several times. Remsburg recently moved into a new home purchased by a nonprofit that helps disabled Army Rangers, and the president brought along White House beer as a housewarming gift, the White House said.

The Phoenix VA Medical Center prompted the scrutiny last year following reports that dozens of veterans died while awaiting treatment at the hospital. The ensuing scandal prompted the ouster of VA Secretary Eric Shinseki. The agency’s Phoenix director, Sharon Helman, also lost her job.

A series of government reports said VA workers throughout the country had falsified wait lists while supervisors looked the other way. While veterans encountered chronic delays, the reports found managers who falsely appeared to meet on-time goals received bonuses.

In the aftermath, Congress approved a sweeping law to overhaul the VA and appropriated money to make it easier for veterans to get VA-paid private health care. It also limits the time VA employees have to appeal firings for alleged wrongdoing.

The Phoenix office brought a respected former director out of retirement to take controls of the office for a one-year assignment. Glen Grippen told an Arizona legislative panel this week that the Phoenix office has hired 320 new staff since January 2014, is opening three new Phoenix-area clinics and is preparing to remodel its main Phoenix hospital.

But the doctor who sounded the alarm on problems with the Phoenix VA and helped bring about the changes said he is still frustrated about what he sees as a slow pace in reforms being carried out. He said McDonald has a nearly impossible job.

“If I ask you to go out and lift a 10,000-pound boulder and you go out and give it your best and can’t do it, does that make you a bad guy? No. The boulder was just too big for anyone to lift,” Dr. Sam Foote said. “And that’s somewhat of the situation that they’re in.”