U.S. and Iranian leaders traded further threats on Saturday as the interim deal to end the war buckles under repeated crossfire in the Middle East.

President Donald Trump upped threats of further missile attacks against Iran in a string of comments on his Truth Social that came after senior U.S. officials demanded that Iran make a public statement saying the Strait of Hormuz is open and that ships crossing the vital corridor won’t be attacked.

Trump also made the comments after the funeral of Supreme Leader Ayatollah Ali Khamenei saw open calls for the U.S. leader’s killing.

Later Saturday, Iranian Supreme Leader Mojtaba Khamenei vowed that Iranians would continue to avenge the killing of his father, Ali Khamenei, who was mourned in funeral events throughout Iran this week. He said in remarks carried by state television that such revenge “is the will of our nation and must certainly be carried out.”

So far, Tehran has not submitted to U.S. demands over the Strait of Hormuz, instead insisting that the route remain under its control and that it be allowed to charge ships moving through it.