Venezuelan President Hugo Chavez is mocking critics who question his close relationship with Iran by showing off what he calls an “atomic bicycle.”

The bicycles are produced in Venezuela under a joint venture with an Iranian company.

Chavez rode one of the bikes during his Sunday TV program and joked about what he called the bicycle’s “radioactivity” and offered one to U.S. President George W. Bush.

U.S. officials say Chavez is a destabilizing influence in Latin America and also express concern that Iran’s nuclear research program could be aimed at weapons production.

Chavez says there is no cause for concern and says the new bicycle factory will eventually be able to manufacture 100,000 bikes a year.