PHOENIX - The director of the Phoenix VA hospital system said Thursday it will take more time to improve the hospital.

A recent internal Veterans Administration list still ranks the Phoenix VA at one out of five stars, near the bottom of the list. The Phoenix VA also rated one star in 2016, before RimaAnn Nelson took over.

"It takes some time to change because there are many factors that go into that rating," Nelson said. She cited both employee surveys and patient surveys as being the driving factors behind the VA ranking system.

The Phoenix VA has been the center of the nationwide VA scandal since 2014, when revelations that veterans died while waiting for care came to light.

Nelson was the seventh director at the Phoenix VA in three years.

Nelson came to Phoenix from a small VA clinic in the Philippines. Before that, she was the head of the St. Louis VA during a time when the hospital accidentally exposed hundreds of veterans to diseases like hepatitis and HIV. The Veterans Administration said Nelson acted quickly to fix those problems.

At the time she was named director of the Phoenix VA, Nelson was widely panned by members of Arizona's congressional delegation.

Former Congressman Matt Salmon asked if Nelson's appointment was "a cruel joke", according to the Arizona Republic. Current Representative Kyrsten Sinema called her appointment "outrageous", according to the paper.

"It's understandable that they had some concerns," Nelson said Thursday. "I'm committed to being here and I'm committed to do whatever it takes."

Nelson admitted there is still a waiting list for some doctors at the VA. But she emphasized that mental health care was available on the same day for veterans "in crisis." But for veterans seeking routine mental health care, she said there is a waiting list.

"There's a shortage of these specialty areas in the country, so it's not just the VA," Nelson said.