Brazilian Foreign Minister Celso Amorim said Tuesday Brazil would maintain negotiations with Iran on uranium enrichment and oppose any sanctions against Iran.

Amorim said Brazil was against the production of nuclear weapons, but Iran had the right to carry out a peaceful nuclear program.

"Dialogue is still possible. What we want is to make sure (that the uranium will not be used to make weapons) through peaceful ways and dialogue," Amorim told reporters.

Under a draft deal brokered by the International Atomic Energy Agency (IAEA), the UN nuclear watchdog, most of Iran's existing low-grade enriched uranium should be shipped to Russia and France, where it would be processed into fuel rods with a purity of 20 percent.

Iran declared on Tuesday it had started the process of producing 20-percent enriched uranium inside the country.

In response to Iran's announcement, the U.S.-led Western countries have warned to take political and economic sanctions against Iran.

For his part, Amorim said he considered any kind of sanctions ineffective and dangerous because they might cross a limit and jeopardize peace.

Iran's president made an official visit to Brazil in November, during which the Brazilian government defended Iran's right to have its own peaceful nuclear program including uranium enrichment similar to Brazil's, following international standards.