In a statement, the ministry noted that UK Defense Secretary Ben Wallace has, himself, confessed to his country’s outstanding debt to Tehran, adding that valid international rulings have also found the UK liable in the case, IRNA reported on Thursday.

International Military Services (IMS), a subsidiary of the British Ministry of Defence, signed contracts in 1971 to sell more than 1,750 Chieftain tanks and armored vehicles to Iran. The deals were canceled after Iran’s monarch Mohammad Reza Shah was deposed during the 1979 Islamic Revolution. Iran, however, had already paid for the tanks, Press TV wrote.

International arbitrators ruled in 2008 that Britain owed the debt that is estimated to stand at £400 million. A previous international ruling had also found that Iran had a right to claim interest on the debt.

The Iranian Defense Ministry’s statement said the IMS refusal to clear the arrears had compelled Iran to resort to international arbitration, adding that the company was still in default of its obligation, although the verdicts have found it liable to pay the debt.

“The relevant authorities in Britain have been trying to shun their responsibility as a liable party on the international arena, especially in the eyes of the Iranian nation,” the statement said.

To try and rationalize their refusal to pay their debt, it added, the UK officials have been citing the United States’ illegal and oppressive sanctions that have come to target the Islamic Republic.

“London is expected to take practical and expeditious steps [in this regard] in order not to further prolong the Iranian government and nation’s dissatisfaction and consternation against England,” the ministry said.

The ministry, meanwhile, denied any link between the case and the issue of Nazanin Zaghari, who was arrested for spying by Iran’s intelligence authorities in April 2016 as she was trying to leave for the UK.

Zaghari was handed a five-year jail term after being found guilty of spying and spreading propaganda against the Islamic Republic.

Hamid Baeidinejad said Iran and the UK were looking at novel ways for the debt to be paid, theguardian.com reported.

Baeidinejad said the size and the interest was agreed between the two parties, and it was natural for discussions to start from how the payment could be made.

The pervasive US sanctions, imposed on Tehran following Washington’s May 2018 withdrawal from a 2015 nuclear deal between the Islamic Republic and the P5+1, make it difficult to make a payment to the Central Bank of Iran.

According to theguardian.com, the possibility of the debt being paid off through medicines and humanitarian goods is being discussed.

Baeidinejad added, “The legal process of this long-running case, which has been going on for more than 50 years, is nearing its end. The court has ordered the British government to pay the Iranian debt plus interest, and this cannot be changed. At the same time, the opposing lawyers have tried to use every legal opportunity to delay the practical execution of the court’s decision.”

He said, “It is natural to come up with ideas for the type of payment as the time comes to pay off the debt, given the complexities and banking problems. The Islamic Republic of Iran also has ideas for expediting the debt. Finalizing the payment method requires a mutual agreement, and talks are underway to determine the details of how the agreements will be implemented.”