The Backstreet Boys were forced to postpone their North American tour after a member of the group entered rehabilitation for depression and alcohol abuse on Monday.

A.J. McLean, a native of West Palm Beach, Fla., entered rehab for 30 days at an unknown location. Fellow band members said he is suffering from anxiety and depression and had been using alcohol excessively.

The other four members of the boy band — Kevin Richardson, Howie Dorough, Nick Carter and Brian Littrell — made the announcement Monday during the MTV show Total Request Live.

Teen members of the live studio audience expressed their emotions as the four members discussed their 23-year-old bandmate's recent problems.

"We didn't want to lie about it. We didn't want to push it under the rug," the 29-year-old Richardson said. "We want to be honest with our fans. He's getting help. He's going to be better."

"He came to us yesterday for the first time. I heard him say, 'Guys, I have a problem and I need to get help.' We figured this was the best for him. It's all about him being healthy," said Littrell, 26.

"When you're trying to help someone who has a serious illness, they have to help themselves first before they can really receive help. They've gotta really want it."

The recent death of McLean's grandmother has been a source of anxiety for him, but he was depressed even before that, Richardson said.

"He's been burning the candle at both ends and partying quite a bit to escape it," he said. "His alcoholism is — it's pretty bad. And we're worried about him."

Carter, 21, said McLean's illness doesn't mean the group is breaking up.

"I don't think there is an end to this group until one of us dies," he said.

Earlier Monday, the Backstreet Boys announced they were postponing remaining sold-out concerts at Boston's FleetCenter this week after Carter injured his hands on Saturday.

The group's tour was scheduled to end in Vancouver, British Columbia on Aug. 7. Now, the tour will resume on that date and end on Sept. 28 in Edmonton, Alberta.

Publicists for the group declined to provide further information about McLean.

The Associated Press contributed to this report.