The world should do everything it can to avoid U.S. attack on Iran, Chavez said at a news conference with London's mayor Ken Livingstone, adding "Europe has an important role to play".

Chavez said he did not believe Iran was seeking to produce an atomic weapon.

"I don't believe that the United States or anyone else has the right ... to prohibit that a country has nuclear energy," said Chavez, who is on a two-day private visit to London at the invitation of Livingstone.

On Sunday afternoon, Chavez addressed a rally in London hosted by Livingstone that a U.S. military attack on Iran would lead to Tehran cutting off its oil supply.

Any attack on Iran would be "terrible escalation" of the conflict in the Middle East, said Chavez.

At the news conference, Chavez also announced a plan to send heating oil to poor people in London for free or at discount prices.

Chavez arrived in London on Sunday after a participation in theEU-Latin American summit held in Vienna, but he will not meet British Prime Minister Tony Blair.

During his trip, Chavez met left-wing members of parliament (MPs), trade unionists and the Mayor of London, Ken Livingstone. Heis scheduled to leave Britain for Libya on Tuesday.