Iran’s military warned Wednesday it will expand its blockade of the Strait of Hormuz to include the Sea of Oman and the Red Sea, unless the United States ends its naval blockade of Iranian ports. Iran’s threat of escalation came as U.S. Central Command said its naval forces have completely halted trade going in and out of Iran by sea, with at least 10 vessels forced to turn around so far.

Meanwhile, the White House said it was optimistic about continuing negotiations between the U.S. and Iran, after a high-level Pakistani delegation arrived in Tehran seeking to lay the groundwork for a second round of talks with the U.S. Pakistani officials said they are expecting a “major breakthrough,” while a spokesman for Iran’s Foreign Ministry said he remained skeptical.

Esmail Baghaei: “It remains to be seen to what extent the other side is truly serious about the claims they’ve made regarding diplomacy. It is the Americans who must prove their seriousness, because they have not only failed to adhere to their commitments many times, but have also fundamentally destroyed the negotiating table.”