WASHINGTON — President Obama on Wednesday expressed outrage about allegations of misconduct at veterans hospitals and said that people in the Department of Veterans Affairs — including Eric Shinseki, its secretary — could be punished if investigations revealed wrongdoing.

Speaking to reporters at the White House after meeting in the Oval Office with Mr. Shinseki, the president said he would take swift action if it was proved that employees of the department manipulated data to hide long wait times for appointments at the hospitals.

“I will not stand for it,” Mr. Obama said. “Not as commander in chief, but also not as an American. None of us should.” He added that if “these allegations prove true,” he would consider the actions “dishonorable.”

“Once we know the facts, I assure you, if there was misconduct, people will be punished,” he said.

The statement from Mr. Obama was the first time he has spoken publicly about the growing furor over the veterans hospitals since he answered a question on the topic during his trip to Asia this month. White House officials are hoping to tamp down political attacks on the subject by demonstrating that the president takes the situation seriously and is prepared to act.