TEHRAN -- A senior inspector of the International Atomic Energy Agency (IAEA) arrived in Iran on Saturday to monitor the implementation of the first step of Teheran's interim nuclear deal, Press TV reported.

Massimo Aparo, who arrived ahead of an IAEA delegation, is scheduled to meet with officials from the Atomic Energy Organization of Iran (AEOI), according to the report.

"The delegation of the agency's inspectors, headed by Mr. Aparo, will report the start of Iran's voluntary measures to the agency on January 20, thus the first step in implementing the Geneva Joint Plan of Action officially will begin," Behrouz Kamalvandi, the AEOI spokesman, was quoted as saying.

On Sunday, Iran and the major world powers finalized an agreement to start the implementation of the Geneva nuclear deal from January 20.