In a video of the incident, the Iranian Revolutionary Guard boat appears to be speeding towards the USS Sirocco, repeatedly hitting its horn. The boat, called the Guard Boghammar, moves away as it closes before a flare shot is heard, but is not visible. The U.S. Navy says Boghammar has reached a distance of 50 meters from Sirocco, increasing the risk of ships colliding with each other on the important waterway. “The Guard’s actions did not meet international standards of professional or safe maritime conduct, increasing the risk of miscalculation and collision,” the US Navy said. Iran did not immediately recognize the meeting, which lasted about an hour and also included two other Iranian ships. The incident comes as tensions remain high due to stalled negotiations over Iran’s nuclear deal with world powers and as the country gains more enriched uranium, bringing its supply closer to arms levels. A similar incident occurred in March, when three Guard ships had a tense encounter with US Navy and Coast Guard vessels as they traveled through the strait. The Navy claimed that the catamaran of the Iranian Shahid Nazeri Guard reached a distance of 25 meters from the USCGC Robert Goldman, as a result of which the US Coast Guard issued multiple warnings via radio and developed flares. Image: The ship passed the US warship very close It came at a time when an agreement between Iran and world powers to restore the nuclear deal seemed possible, before talks broke down. In 2015, the two sides agreed on a nuclear deal, which saw Iran drastically reduce uranium enrichment in exchange for lifting economic sanctions. Three years later, Donald Trump, then president of the United States, unilaterally withdrew the United States from the deal, escalating tensions in the wider Middle East and sparking a series of attacks and incidents. Talks in Vienna on reviving the agreement have been “paused” since March.