The UN nuclear watchdog is opposed to any use of military force against Iran and considers dialogue to be the only means of resolving the country's nuclear problem, the head of the watchdog said Monday.

The head of the United Nations nuclear watchdog said Monday a plan worked out jointly by the agency and Tehran on Iran's controversial nuclear program was "an important step in the right direction."

Iran's top nuclear has said it was "impossible" Tehran would yield to the key Western demand over its nuclear programme, even if the UN Security Council imposed further sanctions.

The Bush administration Friday defended its approach to Iran's nuclear program in the face of implicit criticism from International Atomic Energy Agency director Mohammed ElBaradei. The IAEA chief suggested Washington is in a rush to use military force against Iran, while a U.S. official said ElBaradei is engaged in unhelpful public sniping.

The IAEA says a timetable agreed with Tehran to answer questions about Iran’s nuclear program is a "significant step forward." The statement from the UN nuclear watchdog comes in a report, made public on August 30, that evaluates Iran’s behavior since May.

Western news agencies have quoted a confidential report by the International Atomic Energy Agency (IAEA) as saying that Iran is cooperating with IAEA inspectors to resolve outstanding issues.

The Iranian file on the plutonium issue has been concluded and is closed, the International Atomic Energy Agency said in a document posted on its official Web site Tuesday.

Four inspectors from the UN nuclear watchdog arrived in Tehran Monday to discuss further technical issues in talks aimed at allaying international concerns over Iran's nuclear program, the IRNA news agency said.

Radioactive contamination could delay the work of experts from the UN nuclear watchdog to seal North Korea's nuclear facilities, shut down by Pyongyang under a disarmament deal agreed in Beijing in February, the Kyodo news agency said Wednesday.

Iran's official news agency, IRNA, reports that a group of United Nations nuclear inspectors has visited one of Iran's key nuclear sites.

Another group of inspectors from UN's nuclear watchdog has arrived in North Korea to observe the second phase of Pyongyang's obligation to wrap up its controversial nuclear program, the Xinhua news agency reported Saturday.

Inspectors from U.N. nuclear watchdog agency are expected to join Japanese authorities in collecting information at a nuclear plant, which was quake-damaged. An official said on Friday that they will not oversee their work.