WASHINGTON — Seeking to head off a growing furor over veterans’ health care, President Barack Obama declared this morning that allegations of misconduct at VA hospitals are “dishonorable” and will be not be tolerated by his administration.

“I will not stand for it — not as commander in chief but also not as an American,” Obama said following an Oval Office meeting with embattled VA Secretary Eric Shinseki.

His administration is under mounting pressure from Capitol Hill to address troubling allegations of treatment delays and preventable deaths at VA hospitals.

The VA Inspector General’s office said late Tuesday that 26 facilities are being investigated nationwide — up from 10 just last week — including a Phoenix hospital where 40 veterans allegedly died while waiting for treatment and staff there kept a secret list of patients waiting for appointments to hide delays in care.

Shinseki, a retired Army four-star general, is facing calls for his resignation from some lawmakers. Obama spoke warmly of Shinseki today, saying the secretary had poured his heart and soul into his job, but said there would be accountability if the allegations of misconduct are proven to be true.

“We are going to fix whatever is wrong and so long as I have the privilege of serving as commander in chief, I’m going to keep on fighting to deliver the care and the benefits and the opportunities that you and your families deserve, now and for decades to come,” Obama said.