The tension over Iran's nuclear ambitions isn't easing.

Tehran's top nuclear negotiator says his country will halt all cooperation with the UN nuclear watchdog if the Security Council imposes sanctions.

And he warns Iran will hide its nuclear program if the West takes what he calls "harsh measures."

He says "military action against Iran will not end our program."

He also says Iran will not abide by the Friday deadline set by the Security Council to suspend all uranium enrichment.

Yesterday, Iran's president boldly predicted the Security Council would not impose sanctions and said he was thinking about dropping out of the Nuclear Nonproliferation Treaty.