Iran's supreme leader, Ayatollah Ali Khamenei, has warned that his country will use all its capabilities to defend itself against an attack.
Mr. Khamenei said in a national address Wednesday that if the United States and others want to threaten Iran and enforce coercion and violence, then Iran will respond to an attack by enemies.
He also is quoted as saying that Iran's nuclear activities have been in accordance with international regulations, and that Tehran will continue those actions, despite any action by the U.N. Security Council.
The Council is discussing a draft resolution on toughening existing sanctions against Iran for the country's failure to suspend uranium enrichment.
Earlier Wednesday, Russian Foreign Minister Sergei Lavrov told the Russian parliament that Moscow will not support what he described as excessive U.N. sanctions against Iran for its refusal to suspend enrichment.
The United States and its allies alleged that Iran is working to develop nuclear weapons - a charge that Tehran denies.
The Council's five permanent members, the United States, Russia, Britain, France and China, plus Germany agreed on the proposed new sanctions last week.
Council president South Africa has proposed amendments to the draft, which could delay its adoption for several days.
Some information for this report was provided by AFP, AP and Reuters.