U.S. President Barack Obama, breaking the silence on the Veterans Affairs scandal, declared Wednesday that allegations of misconduct at the country's Veterans Affairs hospitals are "dishonorable" and will be not be tolerated by his administration.

"I will not stand for it (misconduct on Veterans' health care), not as commander in chief but also not as an American," Obama said at a press conference after meeting with U.S. Veterans Affairs Secretary Eric Shinseki.

"If these allegations prove to be true, it is dishonorable, it is disgraceful and I will not tolerate it -- period," he said.

The Obama administration is under increasing pressure from Congress 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 one where 40 veterans allegedly died while waiting for treatment.

"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.

While criticizing the VA scandal, Obama defended embattled Shinseki amid calls for the VA chief's resignation, saying Shinseki "has been a great soldier and nobody cares more about our veterans."

"Across the board he has put his heart and soul in this thing," he added.

Obama's long-awaited remarks marked his first public comments on the matter in more than two weeks. Last week, he dispatched his deputy chief of staff Rob Nabors to the VA to oversee a review of department policies and ordered him to report back to the White House next month.