By Stephanie van den Berg
THE HAGUE (Reuters) - U.S. lawyers urged the International Court of Justice (ICJ) on Tuesday to dismiss an Iranian lawsuit calling for a lifting of U.S. sanctions against Tehran, saying its real aim was to restore a 2015 nuclear pact rejected by President Donald Trump.
The ICJ is the United Nations' highest court for resolving disputes between nations. Its rulings are binding, but it has no power to enforce them, and the United States and Iran are both among a handful of countries that has ignored its decisions.
Iran argues that the reimposed U.S. sanctions, which are undermining its already weak economy, violate a 1955 friendship treaty between the two countries - signed before Iran's 1979 Islamic revolution and the sharp deterioration in bilateral ties that has endured until today.
But U.S. State Department Legal Adviser Jennifer Newstead said on the second day of oral arguments in the case that Iran's appeal based on the 1955 Treaty of Amity was a legal dodge.
"Iran is endeavouring to use the procedures of the Treaty of Amity to enforce rights that it claims under an entirely different (agreement) that specifically excludes judicial remedies," she said.
Newstead said U.S.-Iranian disagreements should be resolved through diplomacy and not by the court.
Trump pulled out of what he described as a flawed 2015 pact between Iran and major world powers under which sanctions were lifted in return for Tehran accepting curbs on its nuclear programme. The Trump administration then announced unilateral plans to restore sanctions against Tehran.
Although Washington’s European allies protested against the move, most Western companies intend to adhere to the sanctions, preferring to lose business in Iran than be punished by the United States or barred from doing business there.
"This case is entirely about an attempt to compel the U.S. by order of this court to resume" the 2015 nuclear deal, Newstead said.
The Trump administration has said its decision to quit the 2015 deal were prompted by U.S. national security concerns, including the threat it says is posed by Iran's nuclear programme and Tehran's involvement in conflicts in Syria, Iraq and Yemen.
Iran asked the ICJ, which is also known as the World Court, on Monday to order Washington to suspend the sanctions temporarily while it hears Iran's case in full, a process that could take years. Washington says that request must be rejected.
A provisional ruling is expected within a month, though no date has been set.
(Reporting by Stephanie van den Berg. Writing by Toby Sterling; Editing by Gareth Jones)