Mediators said Monday the first round of talks between top U.S. and Iranian officials in Switzerland had concluded with some progress after a tense start, with Tehran announcing it had once again closed the Strait of Hormuz and President Donald Trump reiterating threats to resume attacks on Iran.

A joint statement from mediating nations Qatar and Pakistan said the U.S. and ⁠Iran agreed to a roadmap toward a final deal within 60 days. Technical talks will continue for the rest of the week in the Qatari-owned Swiss mountain resort of Buergenstock, according to the statement, which was released by the Qatari Foreign Ministry.

The parties agreed to a mechanism to end the fighting in Lebanon and ​opened a communications line to help ensure safe passages for commercial ships through the contested strait, the statement said.

U.S. Vice President ​JD ⁠Vance began talks with Iranian officials Sunday under the terms of a memorandum of understanding reached last week to extend a tenuous cease-fire from April for at least another 60 days. The discussions continued until the early hours of Monday.

In a post on social media, Iranian Foreign Minister Abbas Araghchi said his country had secured waivers for oil and petrochemical exports, the release of some frozen assets and the launch of a reconstruction and development plan for Iran.