SALVO, North Carolina - Britain's cool, damp weather is likely to cost triple Olympic champion Usain Bolt the opportunity to break his 100 metres world record at the London Olympics, his coach said on Thursday.

Although Bolt has promised something spectacular at the Games from July 27-Aug. 12, coach Glen Mills said breaking his 100 metres record of 9.58 seconds set in Berlin three years ago might be asking too much.

"I'm not sure if London is going to be kind in terms of the temperature," Mills told an international teleconference.

"Given the right conditions like we had in Berlin, it is possible," Mills replied when asked if Bolt could run 9.4 seconds. "He has gotten stronger and he is training very well.

Mills said the main focus for Bolt would be retaining his titles. "The world record would be a bonus," he said.

He said Bolt would not attempt to go one better than Beijing and attempt a gold medal in the 4x400 metres relay as well as the 100, 200 and 4x100.

"The Olympic programme, as set out, does not really allow him to do it," he said. "He would love to do it because he runs great relay legs."

The opening round of the 4x400 on Aug. 9 is the same day  as the 200 metres final. The final of the 4x400 and the first round of the 4x100 will be run on the following day.