Confirming rumors that have been circulating at least since January's American Music Awards, Christina Aguilera [ tickets ] and 'NSync's Justin Timberlake [ tickets ] have announced plans to co-headline a summer tour of North America.

According to promoter Concerts West, 45 concerts are planned in major markets, including New York, Los Angeles, Miami, Chicago, Detroit, Philadelphia and Boston. The outing gets underway on June 4. Dates and venues haven't been announced, but promoters said tour dates and on-sales will be revealed "shortly."

As children, Timberlake and Aguilera co-starred on Disney's "All-New Mickey Mouse Club"--a crew that also included Britney Spears, JC Chasez of 'N Sync and Keri Russell ("Felicity").

"I'm really looking forward to working with Justin," Aguilera said in a statement. "We are going to put on an unbelievable show. Get ready. This is something you don't want to miss."

"I'm looking forward to this tour because it's the first time I'm touring as a solo artist and the first time I'm getting to perform the songs from my CD 'Justified' for my fans," Timberlake said. "This tour with Christina is going to allow the fans to see two great concerts in one night."

The tour is dubbed "Justified and Stripped," combining the titles of recent albums by Timberlake and Aguilera, respectively.

"Justified," Timberlake's solo debut, has been certified double platinum by the Recording Industry Association of America for shipping more than two-million copies in the U.S. The video for the album's second single, "Cry Me A River," has been the most-played video on MTV for the last 4 weeks and is in heavy rotation on BET and VH1.

Multiple Grammy Award-winner Aguilera co-wrote and co-produced her latest album, "Stripped," which is also certified double platinum. Her self-titled debut album sold over 12 million copies worldwide.