VIENNA — A senior U.N. nuclear agency team will visit Tehran on Jan. 28 with Iran saying it is ready after years of refusal to discuss allegations that it was involved in secret nuclear weapons work, diplomats said Thursday.

Diplomats have previously said that International Atomic Energy Agency officials were discussing such a trip with their Iranian counterparts. But before the diplomats’ comments Thursday, no date — or indication that Iran was ready to talk about the allegations — had been mentioned.

Any follow-through on the part of Iran on its reported pledge to discuss nuclear arms suspicions would be significant.

For more than three years, Tehran has blocked IAEA attempts to follow up on U.S. and other intelligence alleging covert Iranian work on nuclear arms, dismissing the charges as baseless and insisting all its nuclear activities were peaceful and under IAEA purview.

Faced with Iranian stonewalling, the IAEA summarized its body of information in November, in a 13-page document drawing on 1,000 pages of intelligence. It stated then for the first time that some of the alleged experiments can have no other purpose than developing nuclear weapons.