Lollapalooza 2012: Live Photos
Frank Ocean performs at Lollapalooza, Day 2 on August 4th, 2012 In Grant Park, Chicago.

"I feel like an asshole right now," says singer, who has canceled European festival dates and a 10-city Coldplay stadium tour

Frank Ocean put an end to his European tour on Saturday, abruptly pulling out of various summer festivals, including Way Out West in Sweden, and a Coldplay stadium tour that would have taken the "Channel Orange" singer to ten major cities starting later this month.

"Let me start by saying I feel like an asshole right now," Ocean said in a statement relayed by Way Out West organizers, "but a tough decision had to be made in regard to my schedule over the next months."

The Odd Future member, who tweeted from Paris on Sunday morning, offered no specifics on his decision. He also canceled festival appearances at the Flow Festival, Pukkelpop, V Festival and Bestival.

On Friday the singer cut short a performance at the Oya Festival in Norway after singing four songs, citing vocal problems. A review in theMusic.com.au said the show was "shaping up excellently at the time" of his disappearance.

Frank Ocean Performs "By Your Side" at Oya, 8/10/12

The "Bad Religion" star was scheduled to perform at the massive Way Out West festival on Saturday. Their explanation was equally vague: "Both Frank Ocean and we hoped hoped for the best, but unfortunately he will not be performing."

Blur Triumph at Way Out West in Pre-Olympic Set

The Coldplay shows were announced in March, well before the explosive success of his debut solo album "Channel Orange," which bowed at No. 2 on the Billboard 200 last month.

The dates, beginning Aug. 28 in Copenhagen, Denmark, would have represented some of the biggest venues for Ocean as a solo artist. The Sept. 2 show would have placed Ocean at the Stade de France in Paris, and there were other stadium stops on Munich, Prague and Warsaw.

At the end of his apology for cutting short his European trek, Ocean sounded contrite, saying he was "Sorry as fu-k, I'll be back if you'll have me."