President Donald Trump said on Tuesday that talks between the U.S. and Iran were neither taking place nor scheduled but the Strait of Hormuz was open, while Iran said the shipping route would remain closed until the U.S. fulfilled the terms of an interim deal.

“There are no talks or conversations going on, or scheduled, with the Islamic Republic of Iran. The Naval Blockade remains in full force and effect. The Hormuz Strait is open and operating. All water mines have been removed or detonated,” Trump said in a post on Truth Social.

Top Iranian negotiator Mohammad Baqer Qalibaf said in comments published by state media on Tuesday that the Strait would remain shut until the U.S. met the conditions of an interim deal signed with Iran in June.

These conditions include the U.S. lifting its blockade of Iranian ports, lifting oil sanctions, releasing Tehran’s frozen assets, and ending threats and military operations on all fronts, Qalibaf told parliament.

On Monday, Jared Kushner, Trump’s son-in-law and special envoy, was optimistic about talks that he said were still underway.

“I can’t go into the details of it, but I will say that the conversations between the U.S. government and different areas of the Iranian government at all areas is probably more robust than it’s maybe ever been,” Kushner told Fox News.

Outward progress towards peace talks and a resumption of oil tanker traffic through the strategic Strait of Hormuz has ground to a halt, threatening to extend the conflict that the U.S. and Israel launched with attacks on Iran on February 28.

A senior Iranian official told Reuters on Monday that Iran will shift to a “fully offensive” military posture because efforts to negotiate a permanent end to the war with the U.S. have stalled.

Asked by reporters on Monday if the U.S. was seeking to extend June’s interim agreement, Trump said no.

(Reporting by Katharine Jackson, Susan Heavey and Daphne Psaledakis;Editing by David Ljunggren and Michelle Nichols )