TEHRAN, Iran – Iran has resumed small-scale enrichment of uranium, a senior Iranian nuclear negotiator confirmed Tuesday, a defiant declaration in the face of global opposition to Iran’s atomic program.

The resumption still leaves Iran a long way from reaching large-scale enrichment of uranium – a process that can produce fuel for an atomic bomb.

Javad Vaeidi, deputy secretary of Iran’s Supreme National Security Council, in announcing the small-scale enrichment, also told reporters that Iran would resume negotiations with Moscow on Monday over its plan to enrich Iranian uranium on Russian soil, a proposal designed to allay fears that Iran is planning to build nuclear weapons.

“The talks with Russia remain valid,” Vaeidi said, adding that an Iranian delegation would go to Moscow.

The negotiations with Russia were due to resume Thursday, but Iran said Monday they had been postponed indefinitely.

Vaeidi gave no indication whether Iran was looking more favorably at the plan now that international pressure over its nuclear program was increasing. Iran has repeatedly said the Russian plan can be complementary to Iran’s nuclear program, but that Tehran would not accept any requirement to scrap uranium enrichment on its own soil.

Vaeidi said enrichment of uranium resumed last week at Natanz, the country’s main enrichment plant, but that Iran had not resumed large-scale enrichment, as required for producing fuel for nuclear reactors.

Later Tuesday, Vice President Gholamreza Aghazadeh said the uranium enrichment work was very limited.

“It can’t be used even at a semi-industrial level. It’s only at the laboratory stage for analyzing research activities,” he said.

The enrichment cannot be used for producing nuclear fuel, he added.