Switzerland continues to provide a discreet setting for US-Iran talks, with the first round expected to take place on Sunday.
The talks come as a 60-day clock begins for negotiations to finalize a nuclear deal between the two nations.
White House envoy Steve Witkoff has left for Switzerland, while Iranian foreign minister Abbas Araghchi is set to arrive on Friday.
Qatar Prime Minister Mohammed Bin Abdul Rahman al-Thani has already arrived in Switzerland, serving as a key mediator between Washington and Tehran.
Meanwhile, a renewed ceasefire between Israel and Hezbollah has been announced, but clashes in south Lebanon have left at least five dead.
