U.S. President Donald Trump said on Tuesday that the Strait of Hormuz has been cleared of Iranian anti-ship mines nearly six months into the conflict with the Islamic Republic.

“I have just been informed by the United States Navy that all mines have been removed and/or detonated from within the international waters of the Strait of Hormuz,” Trump wrote. “Iran has been notified that any ship or boat placing new mines will be immediately and systematically destroyed.”

Trump previously claimed that the U.S. military had “mine-swept the entire strait” and had “100%” control of the waterway on Aug. 10.

“Through Space Force, we are watching every square inch of the Strait, as we are, also, with Pickaxe Mountain and the already destroyed three other Nuclear sites,” the president stated. “There is a Zero Tolerance policy on mine placement in full force and effect.”

Iran’s continued threat of missile and drone attacks on shipping have spiked maritime shipping costs in the Persian Gulf and slowed the transit of oil across the strait to a crawl.

An oil tanker was hit with an unknown projectile near the strait earlier on Tuesday and its engine disabled.