After a trip to South Asia, Kerry will see Iranian Foreign Minister Mohammad Javad Zarif on Wednesday, a day before negotiators resume with detailed talks in Geneva on January 15, department spokeswoman Jen Psaki told reporters.

En route to India this weekend, Kerry will stop in Munich, Germany, for a private meeting with the Sultan Qaboos bin Said of Oman, whose country played a key role in the secret US-Iran talks that led to an interim nuclear accord with Tehran, she said.

Iran and six powers US, Russia, China, Britain, France and Germany are hoping to agree on a framework by March and a final agreement by June 30 that would address international concerns that Iran is using a civilian atomic energy program to hide efforts to develop nuclear weapons.

Under the terms of the interim deal, the US and other nations are providing relief from sanctions to Iran with an eye toward easing and eventually lifting the penalties if Tehran agrees to a final pact and complies with it.

In Tehran, Iran's official news agency reported that Zarif and the rest of the Iranian delegation would see Kerry, as well as the other delegations, in Geneva before the larger group meets.

Earlier this week, Iran's supreme leader said US cannot be trusted to lift sanctions in a future nuclear deal and that Tehran should instead develop an "economy of resistance."

Kerry's Iran-related meetings in Munich and Geneva will bookend a trip to Ahmedabad, India, where he will lead a US delegation to an international conference of government officials, business executives and innovators that will focus on sustainable economic growth and be opened by India's Prime Minister.

While in Ahmedabad, Kerry will also meet the Prime Minister of Bhutan, in what will be one of the highest-level meetings between the two countries, Psaki said.

After leaving Geneva, Kerry will visit Bulgaria for talks with officials there on security cooperation, energy diversification and the bilateral trade and investment relationship, she said.