Pakistani Prime Minister Shehbaz Sharif said that peace talks set to get underway later Saturday in his country were a “make or break” chance to secure a lasting settlement between the U.S. and Iran.

The Iranian delegation headed by Foreign Minister Abbas Araghchi and Mohammad Bagher Ghalibaf, speaker of the Iranian parliament, were in the Pakistani capital of Islamabad for peace talks with a U.S. delegation led by Vice President JD Vance. Analysts said Vance’s presence “added weight” to the talks.

One key issue appears to be Iran’s control over the key Strait of Hormuz shipping lane.

But even as the talks get underway, questions linger over the status of relations between U.S. ally Isreal and Hezbollah, the Lebanese-based insurgent group backed by Iran. There were reports of renewed clashes between the sides even as negotiators were en route to Islamabad.