Iran has issued a fresh vow to push forward with its nuclear program and North Korea is reported to have test-fired a missile. The developments Sunday came on the eve of today's start of an international conference to review the Nuclear Non-proliferation Treaty, aimed at preventing the spread of nuclear weapons. Iran's supreme leader Ayatollah Ali Khamenei, in a speech broadcast on state television, pledged that Iran would press on with its atomic program no matter who becomes the country's next president in the June 17 elections. Khamenei said Iran does not need permission from anyone to pursue nuclear technology. Iran denies trying to make nuclear weapons. U.S. officials said it was believed that North Korea on Sunday had test-launched what appeared to be a short-range missile into the Sea of Japan. North Korea says it already has a number of nuclear bombs. Representatives from some 190 countries are expected to attend the Non-proliferation Treaty conference at the United Nations to review the strengths and weaknesses of the 35-year-old pact. The conference is to run to May 27.