Iran ? Iran’s top leader warned Wednesday his country will pursue “illegal actions” if the U.N. Security Council insists it halt uranium enrichment, an apparent reference to nuclear activities outside international regulations.

Ayatollah Ali Khamenei also warned the United States that Iran would fight back with “all its capacities” if attacked.

“Until today, what we have done has been in accordance with international regulations,” Khamenei said. “But if they take illegal actions, we too can take illegal actions and will do so.”

He did not elaborate on what the “illegal actions” could be, but Iran is a signatory to the Nuclear Nonproliferation Treaty, the agreement under which the U.N. inspections are held.

Iran says it will never give up its right under the treaty to enrich uranium and produce nuclear fuel. But it has offered to provide guarantees that its nuclear program won’t be diverted toward weapons – as the U.S. and some of its allies fear.