Iran’s capture of a South Korean-flagged tanker at sea last week has been described by the US as extortion. But Tehran says it is Seoul that is the hostage taker — accusing it of holding $7bn of its cash. Just weeks before US president-elect Joe Biden is due to take office, the Islamic regime engaged in two moves seen as highly provocative by the west. It decided to boost uranium enrichment to 20 per cent, a further breach of levels agreed in a 2015 nuclear agreement abandoned by the US and a move that could complicate talks between Mr Biden and Tehran.

The seizure of the ship is part of a long-running dispute over $7bn of Iranian cash trapped in South Korean banks and reflects increased pressure inside Iran for the release of tens of billions of dollars it says are held in Chinese, Indian and Iraqi banks because of concerns about US sanctions. “First, our calculation is that Americans cannot do anything now when their generals are busy trying to calm down Republicans and Democrats,” said a regime insider close to hardline forces in

Tehran, referring to tensions in the US ahead of the inauguration. “Second, Iran’s two steps were neither related to each other nor were meant to provoke the US. Seizure of the tanker was an economic decision to force South Korea to unfreeze billions of dollars of our money.”

The Islamic republic, which has been struggling with US sanctions, is under massive economic pressure and battling the worst coronavirus crisis in the region. The seizure of the Hankuk Chemi on Monday, allegedly for pollution, follows Iran’s complaint last month about the difficulty in transferring €180m from Seoul to buy coronavirus vaccines.

“They [the Koreans] needed a slap in the face, after our quarrels bore no fruits, so they realise that they cannot block Iran’s money when we are desperate to buy medicine and vaccines,” the regime insider said. “They should realise that the answer to our emails is not simply ‘we are sorry’. Now, they have to come and negotiate with us over their tanker when we can whisper in their ears: ‘where