Negotiators from Iran and the U.S. prepared for high-level talks with their ceasefire still shaky Friday, as Israel and Hezbollah traded fire and Tehran maintained its stranglehold on the Strait of Hormuz.

There remain many issues that could derail the truce — as well as negotiations for a broader deal to end the war permanently.

Iran’s semiofficial Tasnim news agency, close to the Revolutionary Guard, claimed that talks set for Saturday wouldn’t happen unless Israel stopped its attacks in Lebanon. And U.S. President Donald Trump complained that Iran was “doing a very poor job” by not allowing the free flow of ships through the strait, through which 20% of the world’s traded oil once passed.

Kuwait, meanwhile, said it faced a drone attack Thursday night that it blamed on Iran and its militia allies in the region. Though Iran’s paramilitary Revolutionary Guard denied launching any assault, it has carried out attacks across the Mideast in the past that it did not claim.

And yet, preparations for the talks between Iran and the U.S. in Pakistan appeared to move forward, with U.S. Vice President JD Vance set to take off from Washington. Negotiations between Israel and Lebanon, meanwhile, are expected to begin next week in Washington, according to a U.S. official and a person familiar with the plans, who spoke on condition of anonymity due to the delicacy of the matter.