The United Nations' nuclear agency says it will inspect Iran's heavy-water nuclear reactor early next week. 

The deputy director of the International Atomic Energy Agency (IAEA) announced inspectors' plans to visit the reactor after a meeting in Vienna Tuesday with Iranian negotiators.

Iran agreed two weeks ago to allow inspections by the end of this month as part of an agreement aimed at resolving questions about its nuclear activities.

The disputed reactor, located in the industrial city of Arak, will produce plutonium once it is completed.

Enriched uranium and plutonium can be used to build nuclear weapons, but Iran claims its nuclear program is for peaceful purposes only.

The U.N. Security Council has already imposed two sets of sanctions on Iran, because of its refusal to suspend uranium enrichment, and there are calls for more.

The United States and its Western allies accuse Iran of trying to develop nuclear weapons.

Iran's deputy national security chief, Javad Vaeidi, and its ambassador to the IAEA, Ali Asghar Soltanieh, headed the country's delegation to Tuesday's talks in Vienna.