Britain is working on the basis that Iran is responsible for attacks on two oil tankers in the Gulf of Oman on Thursday, and warned Iran that these actions were "deeply unwise", Foreign Secretary Jeremy Hunt said.
"This is deeply worrying and comes at a time of already huge tension. I have been in contact with (U.S. Secretary of State Mike) Pompeo and, while we will be making our own assessment soberly and carefully, our starting point is obviously to believe our US allies," Hunt said in a statement.
"We are taking this extremely seriously and my message to Iran is that if they have been involved it is a deeply unwise escalation which poses a real danger to the prospects of peace and stability in the region," he added.
Pompeo told reporters earlier on Thursday that the US government believed Iran was to blame, based on the weapons used, the level of expertise needed to execute the operation, and other factors.