Iran must immediately stop its “destabilising activity” in the Middle East, Dominic Raab said, as Tehran faced international pressure over the Mercer Street attack.
Nato condemned the attack on the tanker, which left a Briton and a Romanian dead, and called on Iran to “respect its international obligations”.
The European Commission also spoke out on the attack, although it said the circumstances of the incident in the Arabian Sea off the coast of Oman “have to be clarified”.
The UK, US, Romania and Israel have all blamed Iran for being behind the attack, which is believed to have involved an explosive-laden drone, but Tehran has dined involvement.
A Nato spokesman said: “Freedom of navigation is vital for all Nato allies, and must be upheld in accordance with international law.
“The United Kingdom, the United States, and Romania have concluded that Iran is highly likely responsible for this incident.
“Allies remain concerned by Iran’s destabilising actions in the region, and call on Tehran to respect its international obligations.”
Mr Raab welcomed the Nato statement, adding: “We believe this was a deliberate, targeted attack by Iran – it must end its destabilising actions immediately.”
European Commission spokeswoman Nabila Massrali joined the condemnation and told reporters: “The exact circumstances of this attack have to be clarified and we take note of investigations carried out by the United States, the UK and Israel – this is an action that was against freedom of navigation in this area, and of course unacceptable.
“We oppose any action that would be detrimental to peace and stability in this area and the EU will continue to follow developments closely.”
The strike on the vessel last Thursday has been linked to tensions between Iran and Israel which have seen at least three other Israeli-linked ships targeted since February.
The Mercer Street is managed by London-based Zodiac Maritime, part of Israeli billionaire Eyal Ofer’s Zodiac Group.
The incident comes at a time of political change in Iran, with hardliner Ebrahim Raisi set to be inaugurated as the new president, succeeding Hassan Rouhani.
Iran’s supreme leader Ayatollah Ali Khamenei officially endorsed his protege Mr Raisi on Tuesday.
He advised Mr Raisi, a former judiciary chief, to “empower the country’s poor people and improve the national currency”.