U2 have postponed the announcement of dates for their world tour in support of How to Dismantle an Atomic Bomb. The band had planned to announce the U.S. and international dates on Monday, but that has been put off indefinitely, according to manager Paul McGuinness.

"We've postponed the announcement of the tour because the routing is still being worked on," McGuinness said in a statement. "As soon as we get everything confirmed over the coming weeks, we'll let you know." A band spokesperson would not comment on media reports that the postponement was due to a family illness.

In December, McGuinness said that the tour was slated to kick off on March 1 in Florida and hit 35 U.S. arenas before heading overseas, and it's possible that the tour could still follow that plan.

The band spokesperson would also not comment on whether the change in tour plans would affect U2's attendance of the Grammy Awards ceremony on February 13 -- they are nominated for three awards for their single "Vertigo" -- or their induction into the Rock and Roll Hall of Fame on March 14.

The next U.S. single from the band will be "All Because of You." The video for that song debuted Tuesday night during the Orange Bowl.