The U.N. nuclear agency says talks with Iran on Tehran's nuclear program have been postponed until February 8.
The International Atomic Energy Agency says the delay was granted at Tehran's request, but the agency did not say what motivated the request.
Talks were originally scheduled for January 21, a day after Iran and world powers are set to begin implementation of an interim nuclear pact reached in November.
That deal calls for Iran to limit its uranium enrichment, which the West says was aimed at building nuclear weapons. In exchange, the United States and European Union agreed to ease economic sanctions on Tehran.
The U.N.'s International Atomic Energy Agency wants Iran to provide guarantees of transparency about its nuclear program, and information about alleged past attempts to develop atomic weapons.
Iranian President Hassan Rouhani said Tuesday that the November deal meant the world has given into Iran's demands.
"The Geneva agreement means the wall of sanctions has broken," he said. "The unfair sanctions were imposed on the revered and peace-loving Iranian nation."
The six world powers that negotiated the interim pact — Britain, China, France, Germany, Russia and the United States — are holding separate negotiations with Iran on reaching a permanent agreement.
According to Reuters report that cites Iran's Atomic Energy Organisation said, "U.N. inspectors will travel to Iran on Saturday 'to implement the first step' of the accord."
Some information for this report was provided by Reuters.