Mr. Lauer’s abrupt downfall comes amid a head-spinning series of harassment and abuse claims that have toppled powerful men in journalism, comedy, Hollywood and Silicon Valley, including the movie mogul Harvey Weinstein and another famed television morning host, Charlie Rose of CBS.

By Thursday, NBC had received at least three complaints related to Mr. Lauer, including from a former employee who said that the anchor sexually assaulted her in his office in 2001. Another woman, who spoke with NBC executives on Monday evening, described interactions with Mr. Lauer that began while covering the 2014 Winter Olympics in Sochi, Russia.

Mr. Lauer’s statement concluded: “Repairing the damage will take a lot of time and soul-searching and I’m committed to beginning that effort. It is now my full-time job. The last two days have forced me to take a very hard look at my own troubling flaws. It’s been humbling. I am blessed to be surrounded by the people I love. I thank them for their patience and grace.”

A fixture of American living rooms for more than two decades, Mr. Lauer was uncharacteristically silent on Wednesday in the wake of his firing, which left the television industry stunned and dominated headlines around the country. His former co-host on the “Today” show, Savannah Guthrie, read his statement aloud at the start of Thursday’s 7 a.m. broadcast, saying the program had received Mr. Lauer’s remarks just moments before going on air.

“It is a difficult morning here again,” Ms. Guthrie said at the beginning of the show, as headlines flashed onscreen about “Troubling Allegations” involving the man who, until Tuesday, had welcomed millions of Americans every morning to the same broadcast.