IRAN has sued the United States at the International Court of Justice in a new, if dubious, strategy to nullify the nuclear sanctions reimposed by U.S. President Donald Trump, which are starting to inflict pain on Iran’s already troubled economy.

The International Court of Justice, the principal judicial organ of the United Nations, said in a statement Tuesday that the lawsuit was based on a treaty signed by Iran and the United States more than a half-century ago — well before the 1979 Islamic Revolution that overthrew the American-backed shah and ushered in the prolonged estrangement in relations between the countries.

The United States vowed to fight what it called a “baseless” lawsuit. Trump ordered the nuclear sanctions reimposed May 8 as part of an announcement withdrawing his government from the 2015 nuclear agreement negotiated by Iran and major powers, including the United States, under the Obama administration.

Trump has assailed that agreement, which lifted the sanctions in return for Iran’s verifiable pledges to use nuclear power peacefully, as “the worst deal,” despite support for it by the other participants, including Britain, France and Germany, major American allies.

The International Atomic Energy Agency, the anti-proliferation monitor of the United Nations, has repeatedly said the nuclear agreement is working.

But the accord’s future is in grave doubt over the Trump administration’s decision to abandon it. Iranian officials have said they are preparing to renounce the accord if European participants cannot find a solution.

“We are, of course, continuing to carry out and implement our obligations,” a spokesman for Iran’s Atomic Energy Organization, Behrouz Kamalvandi, told reporters in Tehran. “But at the same time, taking every scenario into consideration, we are preparing ourselves.”

Meanwhile, U.S. Secretary of State Mike Pompeo has rejected a high-level appeal from the EU for exemptions from sanctions against Iran, throwing into doubt billions of euros worth of trade.

Senior officials from Britain, France and Germany had pleaded with the U.S. not to impose sanctions next month on European companies which do business with Iran.

In a letter to the nations’ finance and foreign ministers, Pompeo and Treasury Secretary Steven Mnuchin rejected the appeal, saying America wanted to exert “unprecedented financial pressure” on Tehran after Trump pulled out of the nuclear deal in May.

Pompeo added that the U.S. will not ease the sanctions until it sees a “tangible, demonstrable and sustained shift’’ in Iran’s policies. “The president withdrew from the Iran nuclear deal for a simple reason — it failed to guarantee the safety of the American people,’’ Pompeo and Mnuchin wrote in a letter leaked to the press earlier this week.

The letter was a response to an appeal from the three European countries last month, in which they said they “strongly regret” the U.S. decision to withdraw.

(SD-Agencies)