"Iran launched missiles, drones and small-boat attacks at U.S. warships near the Strait of Hormuz, and that the U.S. responded by intercepting the threats and striking Iranian military sites responsible for the attacks."

Iran attacked, the US blocked and countered, attacking the source of the attacks.

Per centcom:

> “Iranian forces launched multiple missiles, drones and small boats as USS Truxtun (DDG 103), USS Rafael Peralta (DDG 115), and USS Mason (DDG 87) transited the international sea passage. No U.S. assets were struck.”

Step 1 appears to have been US ships entering the strait. Iran claims they fired on a tanker but who's to say.

During the short stint of "Project Freedom", the US claimed to have attacked seven Iranian ships. Which is still not the first time the US has attacked Iran during a negotiation or ceasefire.