Iran on Friday demanded that the British navy release an Iranian oil tanker seized last week off Gibraltar, accusing London of playing a "dangerous game" and threatening retribution, while London announced it was sending a destroyer to the Persian Gulf.
The comments from Iran's Foreign Ministry came the day after police in Gibraltar, a British overseas territory on the southern tip of Spain, said they arrested the captain and chief officer of the supertanker suspected of breaching European Union sanctions by carrying a shipment of Iranian crude oil to Syria.
Foreign Ministry spokesman Abbas Mousavi told Iranian state news agency IRNA that "the legal pretexts for the capture are not valid ... the release of the tanker is in all countries' interest."
"This will ensure that the UK alongside international partners can continue to support freedom of navigation for vessels transiting through this vital shipping lane."
Iranian Foreign Minister Mohammad Javad Zarif scoffed at the accusation Iran was violating sanctions, which he said "are meant "to stop Europe from buying Syria's oil, they are not about another country selling oil to Syria."
"This is a very childish and ridiculous excuse by the British," he said. "They should officially announce that we are servants of America and act on behalf of America. America has returned their favour well by insulting their ambassador and their prime minister."
A Foreign Ministry spokesman in Beijing said that international trade with Iran "within the framework of international law is reasonable and legitimate and deserves to be respected and protected."