The US dates follow the band's earlier announcement of a March trek through Canada, ending with a March 30 one-off at New York's Radio City Music Hall, a date which sold out in a "matter of minutes," according to the group's publicist.

The new dates kick off April 22 in Phoenix and will see the group canvas 20 cities across the country, starting off on the West Coast and slowly moving eastward. Tickets go on sale to the public March 9, except for the May 2 Houston date, which will go on sale March 17. A special fan presale for all dates will take place Wednesday (3/7) beginning at noon EST. More information on the presale can be obtained at a special website set up by the group.

Opening support for the trek will include fellow metal icons Megadeth, who will preview material from their forthcoming new album, "United Abominations," due in stores May 8. Additional support will come from Machine Head, backing its new album, "The Blackening," which is set for a March 27 release.

The reunion of Dio and his one-time Sabbath bandmates came about when the musicians convened in a studio last year to record three new songs for the era-spanning compilation "Black Sabbath: The Dio Years," which is due out April 3 from Rhino Records.

The sessions "went so well that the band agreed to satisfy longstanding demands for a reunion tour," according to a press release.

When the planned collaboration was announced last October, Ozzy Osbourne, Black Sabbath's original (and, officially, current) singer, was quick to issue a press release through his publicist commenting that "there is only one Black Sabbath," and that Osbourne's work with the band will continue.

Dio filled in for Osbourne twice during the '80s and '90s, when the latter was temporarily asked to leave the band to deal with his substance abuse problems.

Heaven and Hell takes its name from the title of the 1980 Black Sabbath album that was the group's first with Dio at the helm.