Wladimir Klitschko will attempt to regain his world heavyweight titles by taking up his option for a rematch with new champion Tyson Fury next year.
Fury beat the Ukrainian in Germany at the weekend to take the WBA, IBF and WBO belts.
The contract for the fight included a clause for a rematch, for which the date and the venue have to be decided.
"Failure is not an option," Klitschko said on his prospects of winning back his titles.
"I was really frustrated directly after the fight, but after some short nights, I now know that I am much better than my performance then," the 39-year-old said.
"I couldn't show much full potential at any time. This is what I want to change in the rematch, and I will."
Klitschko has had two spells as world champion, the first from 2000 to 2003. Having regained the WBO belt in 2004, he went 11 years and 19 successful defences before losing to Fury on Sunday.
Manchester fighter Fury said on Monday that he would beat Klitschko again if they were reunited in the ring next year.
"Wembley Stadium would be very appealing at the right time of year, definitely," he said. "It was close to 55,000 in Düsseldorf. It would easily do 80,000 at Wembley. But it would have to be at the end of the football season."