President Bush says Iran's decision to freeze its uranium enrichment programs is a positive step, but "not the final step."

Speaking at a joint press conference in Canada Tuesday, Mr. Bush said Iran must go further and terminate its nuclear activities. He also says the world must be able to verify if Tehran will keep its word.

Iran agreed Monday to suspend its nuclear activities after reaching an agreement with European negotiators. The agreement staved off a U.S. push to bring the matter to the U.N. Security Council for possible sanctions over Tehran's alleged nuclear weapons program.

But Iran says it has not abandoned its right to enrich uranium, and says its agreement will end in "several months."