Billionaire Jim Rogers said that oil prices will rise well over $100 a barrel. The U.S. investor said that it will remain high as part of a sustained commodities bull run which has another 15 years left.

However, a factor that would bring down the price would be the avian flu epidemic. He said the bird flu would all asset classes to fall, although oil would probably be less of a concern.

Rogers told Reuters, "We're going to have high oil prices for a very long time. The surprise is going to be how high it goes."

He added that oil "will be much more than $100 before the bull market is over."

U.S. light sweet crude oil hit a new high of $75.40 a barrel on Wednesday and is trading close to $75 on Thursday.

Rogers re-iterated, "It's a major long-term bull market as far as I'm concerned."

The billionaire concluded that the impact of tensions involving Iran's nuclear weapons and North Korea's missile launches would be temporary.