Diplomats from five countries toured one of Iran's primary nuclear facilities on Saturday — an attempt by the Islamic republic to show that its atomic program is for peaceful ends and not a cover for nuclear weapons.

The visit to the Isfahan Uranium Conversion facility in central Iran comes ahead of a United Nations deadline for Iran to halt uranium enrichment by later this month.

If Iran does not stop enrichment by the end of the 60-day period stipulated by the U.N., the Security Council will consider additional measures beyond the economic sanctions it approved Dec. 23.

"The message of this visit is that Iran is determined to continue its peaceful nuclear activists," Ali Ashgar Soltanieh, head of the Iranian delegation to the International Atomic Energy Agency, told the diplomats from Sudan, Malaysia, Cuba, Egypt, and Algeria — representing the Nonaligned Movement, the Group of 77 and the Arab League.

Soltanieh also described the tour as "an opportunity to see that the IAEA has full surveillance control over the activities of this facility."

The diplomats represent organizations that have a long history of asserting members' rights to pursue their national interests and broadly those of developing countries without being fettered by Western countries.

The Nonaligned Movement was formed in 1954 by several Third World countries that declared they would not take sides in the Cold War, while the G-77 is a grouping of 130 countries from the South. The Arab League is a regional grouping representing with 22 member states.

Inspectors from the U.N. nuclear watchdog, the International Atomic Energy Agency, visited the Isfahan facility twice in January.

International concerns have recently focused more on the facility in Natanz, where uranium can be enriched using cascades of 164 centrifuges installed above ground. Iranian officials have announced plans to operate 3,000 centrifuges below ground enabling it to speed up its production of nuclear fuel.

Diplomats accredited with the IAEA in Vienna, Austria said hundreds of technicians and laborers had been "working feverishly" at the Natanz underground facility over the past few weeks, setting up piping, control panels and electric cables.