Updated

The Veterans Affairs Department is considering disciplinary action against more than 1,000 employees as it struggles to correct systemic problems that led to long wait times for veterans seeking health care and falsification of records to cover up delays, VA Secretary Robert McDonald said.

In an interview with the CBS News program "60 Minutes," McDonald said the VA is taking "aggressive, expeditious disciplinary action, consistent with the law" against more than 1,000 of its 315,000 employees.

McDonald said the disciplinary report given to the Veterans Affairs committees in the House and the Senate "has about 35 names on it. I've got another report that has over 1,000" names, McDonald said.

The interview with "60 Minutes" will be broadcast on Sunday. An excerpt was set to air Friday on the "CBS Evening News."

McDonald's comments represent a departure from his previous public remarks. At a news conference Thursday, he said the VA has proposed disciplinary action — up to an including firing — against more than 40 employees nationwide since June.

The VA has been under intense scrutiny since a whistleblower reported that dozens of veterans may have died while awaiting treatment at the Phoenix VA hospital, and that appointment records were falsified. Since then problems have been revealed at VA health care sites across the country.

The scandal led to the ouster of former VA Secretary Eric Shinseki and to a new law making it easier for veterans to get VA-paid care from local doctors. The agency has been overwhelmed by the influx of veterans from wars in Iraq and Afghanistan, the aging of Vietnam War veterans and expanded eligibility for benefits as a result of exposure to Agent Orange and other problems.

Some Republican lawmakers have criticized the VA for moving too slowly to fire managers involved in covering up wait times and other problems.

But McDonald said the agency is moving as fast as it legally can. All VA firings are subject to review by an administrative judge.

"We've got to make it stick," McDonald told CBS. "We propose the action, the judge rules and the individual has a time to appeal."

What the VA is "most concerned about is caring for veterans. So if someone has violated our values and we think has done bad things, we move them out," McDonald said. "And that's why we have a lot of people on administrative leave. We move them out. We don't want any harm to our veterans."

Only one of four senior employees recently targeted for removal by the VA has been fired, a fact Republican lawmakers cite in criticizing McDonald's implementation of the new law, which gives McDonald wide authority to fire poor-performing employees and streamlines the appeals process.

Two of the targeted employees retired. A third was granted an extension allowing her more time to reply to the VA's decision.