Four ships belonging to Iran's Islamic Revolutionary Guard Corps (IRGC) "harassed" an American destroyer in the Strait of Hormuz Tuesday, a U.S. Navy official confirmed to Fox News.
The official said the Iranian ships carried out a "high-speed intercept," with two of the vessels coming within 300 yards of the USS Nitze.
The Navy official described the incident as "unsafe and unprofessional," adding that the Iranian ships "created a dangerous, harassing situation that could have led to further escalation."
The USS Nitze was accompanied by the guided missile destroyer USS Mason on what the official described as a "routine transit" in international waters at the time of the incident.
As the Iranian ships closed in, the official said the Nitze attempted to make radio contact 12 times with no response. As the Iranian ships continued their approach, the destroyer sounded five short blasts on its whistle, an international danger signal.
The official said the Nitze was ultimately forced to change its course to avoid the Iranian ships, despite coming close to offshore oil rigs.
In January, ten U.S. sailors were detained by the IRGC after their patrol crafts inadvertently entered Iranian waters. They were released after being held for approximately 15 hours.
U.S. military officials estimate there are now 100,000 Iranian-backed forces in Iraq, with thousands more believed to be in Syria.
Last month, Gen. Joseph Votel of U.S. Central Command said that 90 percent of interactions between American and Iran ships at sea were "safe and professional."
Fox News' Lucas Tomlinson contributed to this report.