Dominic Raab urged the UN Security Council to respond to Iran's destabilising actions after a deadly tanker attack last week off the coast of Oman, which the UK Foreign Secretary blamed on Tehran.
"The council must respond to Iran’s destabilising actions and lack of respect for international law," he said.
Britain, Romania and Liberia told the UN on Tuesday that it was “highly likely” that Iran used one or more drones to carry out the assault.
“This attack disrupted and posed a risk to the safety and security of international shipping and was a clear violation of international law,” the countries said in a letter to the 15-member council, which was seen by Reuters.
“This act must be condemned by the international community.”
Iran has denied any involvement in Thursday's attack on the Mercer Street – a Liberian-flagged, Japanese-owned petroleum-product tanker managed by Israeli-owned Zodiac Maritime.
Two crew members, a Briton and a Romanian, were killed in the incident.
Diplomats said Britain was expected to raise the issue in a closed-door meeting of the Security Council in the coming days.
The council is also, coincidentally, scheduled to discuss maritime security in a public meeting on Monday, headed by Indian Prime Minister Narendra Modi. India is council president for August.
“The United Kingdom and Romania, along with regional and international partners, are conducting a thorough investigation of this attack. We will update the council in due course,” Britain, Liberia and Romania said in the letter.
The US and Britain said on Sunday they would work with their allies to respond to the attack.