Hoda Kotb has been named a permanent co-anchor of the Today show alongside Savannah Guthrie following Matt Lauer's firing amid sexual harassment allegations.

Lauer's ouster in November left a major opening for the morning program, which Kotb filled temporarily until the announcement Tuesday made her position permanent.

"This has to be the most popular decision NBC News has ever made," Guthrie said at the top of the broadcast.

NBC News chairman Andy Lack shared the news in a staff memo Monday morning. "I'm proud to share the news with you that Hoda Kotb will become co-anchor of Today, joining the inimitable Savannah Guthrie," he wrote. "Our new anchor team will officially make their on-air debut this morning. Over the past several weeks, Hoda has seamlessly stepped into the co-anchor role alongside Savannah, and the two have quickly hit the ground running."

NBC fired Lauer Nov. 29 after receiving what NBC News chairman Andy Lack called a "detailed complaint" about "inappropriate sexual behavior in the workplace." NBC News reported there may be many as eight accusers, though tallying is difficult as the accounts have been anonymous.

The question of who would replace Lauer, 59, the biggest star of morning television with a nearly 21-year run anchoring Today, swirled over the last month. However, viewers tuned in, bumping up ratings, and the NBC morning show beat ABC's Good Morning America in the first week of December for the first time in three months, according to Nielsen.

Gary Levin contributed to this report.