The Department of Veterans Affairs has lost the trust of veterans and the American people as a result of widespread treatment delays for people seeking health care and falsified records to cover up those delays, the agency's top official said Wednesday.

Acting VA Secretary Sloan Gibson said the VA has created an environment where workers are afraid to raise concerns or offer suggestions for fear of retaliation and has failed to hold employees accountable for wrongdoing or negligence.

The agency also has devoted too many resources to meeting performance metrics -- such as prompt scheduling of patient appointments -- that were subject to manipulation and may not accurately reflect quality of care, Gibson said.

"As a consequence of all these failures, the trust that is the foundation of all we do -- the trust of the veterans we serve and the trust of the American people and their elected representatives --has eroded," Gibson told the Senate Veterans Affairs Committee.

Gibson took over as acting secretary May 30 after VA Secretary Eric Shinseki was forced to resign amid a growing uproar over treatment delays and other problems at VA hospitals and clinics nationwide.

The acting secretary told the Senate panel he is committed to restoring the trust of veterans and the American people through a series of actions, including some that have already begun, including outreach to 160,000 veterans to get them off waiting lists and into clinics.

Gibson also vowed to fix systemic scheduling problems, address cultural issues that have allowed problems at the agency to fester and hold front-line workers and supervisors accountable for willful misconduct or negligence.

He also promised to improve transparency, including regular and ongoing disclosures of information about patient scheduling and care.

Lawmakers generally welcomed Gibson's comments, but said the agency has a long way to go to restore trust.

"What has happened over the course of years is a horrendous blemish on the VA's reputation, and much more work will be needed to repair that damage," said Sen. Richard Burr, R-N.C. "The culture that has developed at VA and the lack of management and accountability is simply reprehensible."

Sen. Patty Murray, D-Wash., also lamented "a corrosive culture" at the VA that she said includes management failures and lack of communication at all levels of the agency.

"VA needs more providers, more space and modern IT systems," Murray said.

Sen. Bernie Sanders, I-Vt., chairman of the Senate veterans panel, said he has been impressed by the response of Gibson and other VA leaders to the current crisis, but added: "The simple reality is that the problems they face are staggering."

VA is the largest integrated health care system in the country, with nearly 9 million enrolled veterans seeking care, including many who suffer from a variety of serious mental and physical health problems.

As of June 15, about 46,000 veterans waited at least 90 days for their first VA medical appointments, the agency said. That's down from 57,000 who waited more than 90 days as of May 15.

An additional 7,000 veterans had never gotten an appointment for VA care, despite seeking one over the past decade, the VA said. That's down from about 64,000 veterans who did not get appointments as of May 15.

More than 630,000 veterans have waited at least 30 days for an appointment, the VA said.