After Israel and Great Britain, the USA also blamed Iran for the attack on the tanker "M / T Mercer Street".
The American government is now discussing with its allies to find an "appropriate response" to the attack, warned Secretary of State Antony Blinken on Sunday.
After examining the evidence, the government assumes that Iran carried out the attack on July 29 with the help of exploding drones.
A British man and a Romanian were killed.
"There is no justification for this attack," emphasized Blinken.
Iran's actions threaten the freedom of navigation, international trade and the crew of ships.
Foreign Minister Dominic Raab had previously announced in London that Great Britain was working with its partners on a reaction to the “unacceptable” attack.
Tehran rejects allegations
Iran has denied allegations from Israel that it was responsible for the attack.
The ship is managed by the British company Zodiac Maritime.
The chairman of the Zodiac group is the Israeli businessman Ejal Ofer, who, according to media reports, also owns shares in the group.
Ships cross the Strait of Hormuz into the Persian Gulf through the Gulf of Oman, which is also bordered by Iran.