Vieira will tape her appearance on the show May 6. Her cameo is part of a series of special visits the "Today" stars are making abroad.
Al Roker is to appear in an original music video called "The Weatherman" on Australia's hit TV show "The Wiggles," and will sing in concert in Australia for 60,000 people May 2.
Natalie Morales will channel her inner soap star and take a leading role in an episode of Telemundo's telenovela, "Los Herederos Del Monte," filmed in Bogota May 3.
On May 4, Ann Curry will guest star on the Danish game show, "Bingo Banko."
Kathie Lee Gifford and Hoda Kotb are to serve as guest hosts on the morning program, "Smile Jamaica," May 5, NBC said.