Despite toughened international sanctions, a new UN inspection reports that Iran continues to stockpile enriched uranium. The International Atomic Energy Agency was unable to comment on the quantity of the nuclear materials, saying that they are often being blocked from investigating sites. However, representatives did say that the agency “remains concerned about the possible existence in Iran of past or undisclosed nuclear related activities,” including the possible “development of a nuclear payload for a missile,” reported the Washington Post. The UN report concluded that Iran has produced 50 pounds of uranium enriched at 20 per cent purification levels. Previously, it had not enriched it more than 5 per cent (90 per cent is considered weapons grade).