The UN nuclear watchdog and Iran will hold talks over Tehran's disputed nuclear program on Feb. 13, a day later than planned, the Vienna-based UN agency said on Tuesday.

The International Atomic Energy Agency and Iran failed in two days of discussions last week to agree to a framework deal to resume a long-stalled IAEA investigation into suspected nuclear bomb research in the Islamic Republic.

The IAEA said after the Jan. 16-17 negotiations that the two sides would meet again on Feb. 12 in Tehran. An IAEA spokeswoman said the date had now been changed, giving no further details.

The UN agency has been trying for a year to negotiate an agreement that would give its inspectors access to sites, officials and documents in Iran.

Western diplomats accuse Iran of stonewalling the IAEA investigation. Iran denies Western accusations that it is seeking to develop the capability to make nuclear weapons, saying its atomic activities are aimed at generating electricity.