NEW YORK — NBC announced Tuesday that it is suspending Brian Williams as “Nightly News” anchor and managing editor for six months without pay for misleading the public about his experiences covering the Iraq War.

NBC chief executive Steve Burke said Williams’ actions were inexcusable and jeopardized the trust he has built up with viewers during his decade as the network’s lead anchor. But he said Williams deserved a second chance.

Williams apologized last week for saying he was in a helicopter that was hit by a grenade while covering the Iraq War in 2003. Instead, another helicopter flying ahead of his was hit, and some veterans involved in the mission called him out on it.

NBC News President Deborah Turness said in a memo that Williams “misrepresented” events that occurred while he was covering the war.

“It then became clear that on other occasions Brian had done the same while telling that story in other venues,” Turness said. “This was wrong and completely inappropriate for someone in Brian’s position.”

Turness said Lester Holt would continue to substitute for Williams as anchor.

Williams had received some key support in the last 24 hours. Fox News Channel host Bill O’Reilly, frequently a critic of NBC News, suggested on Jimmy Kimmel’s show that Williams should keep his job unless more stories come out. Columnist David Brooks in The New York Times suggested there was a need for forgiveness in instances of wrongdoing.

Jon Stewart, of “The Daily Show,” who has hosted Williams as a guest 22 times, criticized Williams for vanity. But he had sharper words for media outlets going after Williams.

“I am happy,” Stewart said. “Finally, someone is being held to account for misleading America about the Iraq War.”

Even with the suspension, Turness said the network’s probe into Williams’ statements is continuing.

Shortly after it happened during a reporting trip to Iraq in 2003, Williams explained on NBC that one of a group of helicopters he had been flying with had been hit by a rocket-propelled grenade. When he appeared with David Letterman a decade later, the story changed to his helicopter had been hit, which Williams now admits is false. It wasn’t until he told the story on “Nightly News” last month and veterans who had been there complained that the embellishment emerged.

In Israel in 2006, Williams explained to his news viewers that he’d been on an Israeli helicopter and saw a trail of smoke and dust where Hezbollah rockets had landed in the Israeli countryside, and he described seeing rockets being launched 6 miles from his location.

The story became more dramatic when he appeared on “The Daily Show” a month later.

“Here’s a view of rockets I have never seen, passing underneath us, 1,500 feet beneath us,” Williams said. “And we’ve got the gunner doors on this thing, and I’m saying to the general, some four-star, ‘It wouldn’t take much for them to adjust the aim and try to do a ring toss right through our open doors, would it?’”

An Israeli army official who traveled with Williams that day, Jacob Dallal, on Tuesday called the anchor’s account “generally reasonable.” He said it was fair to assume rockets flew beneath their helicopter.