Open this photo in gallery Mohsen Mohebi, representative of Iran, is pictured during the opening of case between Iran and the United States at the The International Court of Justice in the Hague, Aug. 27, 2018. JERRY LAMPEN/AFP/Getty Images

Iran warned on Monday that re-imposed U.S. sanctions would cripple its economy and plunge the volatile Middle East deeper into crisis as it urged the United Nations’ highest court to suspend the Trump administration’s economic pressure on Tehran.

In a written statement about the case at the International Court of Justice, U.S. Secretary of State Mike Pompeo called Iran’s claims “meritless” and defended the sanctions as a way of keeping Americans safe.

The world court’s wood-paneled Great Hall of Justice in The Hague is the latest backdrop for Washington and Tehran’s high-stakes dispute about Iran’s nuclear ambitions.

Story continues below advertisement

President Donald Trump said in May he would pull the U.S. out of a 2015 agreement over Iran’s nuclear program and would re-impose sanctions on Tehran. Washington also threatened other countries with sanctions if they don’t cut off Iranian oil imports by early November.

Iran filed a case with the court in July challenging the re-imposition. Tehran alleges that the sanctions breach a 1955 bilateral agreement known as the Treaty of Amity that regulates and promotes economic and consular ties between the two countries.

The treaty was signed when the U.S. and Iran were still allies following the 1953 revolution – fomented by Britain and the U.S. – that ultimately cemented the rule of Shah Mohammad Reza Pahlavi.

However, diplomatic relations were severed following the 1979 Islamic Revolution in Iran and takeover of the U.S. Embassy and ensuing hostage crisis. Despite that dramatic deterioration in relations, the treaty remains in force.

Iran and the U.S. have a history of litigation at the International Court of Justice, in cases covering crises including the embassy seizure and the shooting down of an Iranian passenger jet mistaken by a U.S. warship for a fighter jet.

Rulings by the world court, which settles disputes between nations, are final and legally binding. However, it remains to be seen if the U.S. would abide by a court order to suspend sanctions on Iran.

At Monday’s hearings, Tehran asked judges to urgently order a suspension of the sanctions while the case challenging their legality is being heard – a process that can take years. A decision on the urgent request for a suspension is likely to take weeks.

Story continues below advertisement

Iranian representative Mohsen Mohebi told the court the U.S. sanctions are a clear breach of the 1955 treaty because they are “intended to damage, as severely as possible, Iran’s economy.” He called Trump’s sanctions policy “nothing but a naked economic aggression against my country.”

Mohebi also warned that the sanctions could exacerbate regional tensions.

His comments came a day after Iran’s defence minister said his country will continue its support of the Syrian government to ensure improved security in the region. Israel has expressed concern over Iran’s growing influence in Syria, accusing Tehran of seeking to establish a foothold near the frontier with the Jewish state. The United States has been pressing for Iran to withdraw its fighters from Syria.

Iran’s 2015 nuclear deal, brokered when Barack Obama was still in the White House, imposed restrictions on the Islamic Republic’s nuclear program in return for the lifting of most U.S. and international sanctions against Tehran.

However, the deal came with time limits and did not address Iran’s ballistic missile program or its regional policies in Syria and elsewhere. Trump called the accord the “worst deal ever.”

Some U.S. allies oppose the sanctions and are seeking to keep the nuclear deal alive. Last week, the European Union announced a financial support package to help bolster Iran’s flagging economy.

Story continues below advertisement

Pompeo called the world court challenge an attempt by Tehran “to interfere with the sovereign rights of the United States to take lawful actions, including re-imposition of sanctions, which are necessary to protect our national security.”

The United States, which argues that the court does not have jurisdiction in the case, is to present its legal arguments to judges on Tuesday.

Pompeo said lawyers would “vigorously defend” the U.S. and “and we will continue to work with our allies to counter the Iranian regime’s destabilizing activities in the region, block their financing of terror, and address Iran’s proliferation of ballistic missiles and other advanced weapons systems that threaten international peace and stability. We will also ensure Iran has no path to a nuclear weapon — not now, not ever.”