President Barack Obama’s under-fire Veterans Affairs Secretary Eric Shinseki has resigned, paying the price for an expanding scandal over failures in health care for American veterans.

“A few minutes ago, Secretary Shinseki offered his resignation. And with considerable regret, I accepted,” Obama said.

The president said that an initial review by Shinseki had found that delays and other failures in veterans’ health care were not confined to one facility in Arizona, but were systemic and nationwide.

“As he told me this morning, the VA needs new leadership. He does not want to be a distraction,” Obama said in a hurriedly arranged on-camera statement.

“My assessment is that unfortunately he is right.”

Shinseki’s position had become untenable in recent hours, as lawmaker after lawmaker – including many Democrats running for re-election in November – called for him to quit.

“We don’t have time for distractions. We need to fix the problem,” Obama said.

The president announced that Shinseki’s deputy, Sloan Gibson, would take over on an interim basis until a permanent replacement is found.

Earlier, Shinseki said in a speech that he took full responsibility for the failures.

The former general said that when he first became aware of the problems with the waiting lists he had thought they were isolated cases, but that he had now discovered widespread failings.

Shinseki apologised to all veterans who had been denied care and said he had begun procedures to sack managers at the agency’s office in Phoenix where the scandal first came to light.

Obama said that Shinseki had already begun firing people responsible for misconduct and delays at the VA facility in Arizona.

The inspector general found that 1,700 veterans in the Phoenix area alone had been kept off the main waiting list for primary care. Up to 40 patients are said to have died while waiting for treatment.