The tanker Stena Impero was impounded with its 23 crew members on board at Bandar Abbas

Britain is looking into a series of options to respond to Iran's seizure of a British-flagged tanker, junior defence minister Tobias Ellwood said on Sunday when asked whether London was considering putting sanctions on Tehran.

"Our first and most important responsibility is to make sure that we get a solution to the issue to do with the current ship, make sure other British-flagged ships are safe to operate in these waters and then look at the wider picture," he told Sky News.

Asked about the possibility of sanctions, he said: "We are going to be looking at a series of options ... We will be speaking with our colleagues, our international allies, to see what can actually be done."