The top Iranian and US diplomats held nuclear talks in Munich on Friday afternoon in a meeting attended by experts from the two countries.
According to AP, a US official, who spoke on the condition of anonymity, said Kerry has voiced the US administration's desire to reach the outline of a nuclear deal by the end of March.
Kerry told Zarif in the Friday meeting that Washington wants to meet the March target for the "political framework" of a final agreement to be done by summer, the official noted.
Iran and the Group 5+1 (Russia, China, the US, Britain, France and Germany) are in talks to hammer out a final agreement to end more than a decade of impasse over Tehran’s nuclear energy program.
While scores of foreign and defense ministers have gathered in Munich for the annual security conference, Zarif is planned to hold one-on-one meetings with other representatives of the Group 5+1.
On Friday, the Iranian foreign minister also met his German counterpart Frank-Walter Steinmeier to discuss Tehran’s nuclear program.
Following an interim nuclear deal signed between Iran and the six powers in Geneva in November 2013, two deadlines for a final, comprehensive deal have been missed, and now a third one is looming on July 1.