On Monday, the court is expected to hear the US’s argument that it does not have jurisdiction over the case that was brought to it by the Islamic Republic in July 2018.
Washington’s legal squad is to address the tribunal at 13:00 GMT, while Tehran will present its counterarguments on Wednesday.
The Islamic Republic lodged the case with the ICJ some two months after US President Donald Trump’s administration left a multilateral nuclear agreement with Iran and renewed the bans that the deal had lifted.
Suing the US, Iran argued that Washington had flouted a 1955 Treaty of Amity with Tehran by restoring the sanctions.
Washington responded by quitting the treaty. US Secretary of State Mike Pompeo, a vocal Iran hawk, announced the decision on October 3, saying the “decision is 39 years overdue.”
He called Iran’s case “meritless” and laid into the court for taking up the case. “We’re disappointed that the court failed to recognize that it has no jurisdiction to issue any order relating to these sanctions measures with the United States, which is doing its work on Iran to protect its own essential security interests,” he added.
The court, however, ordered the US to provisionally lift its sanctions on food, medicine, medical equipment, agricultural goods, and airplane parts and services until the tribunal issues its final verdict.
By leaving the nuclear agreement — that has the UK, France, China, Russia, and Germany as its other parties — the US has also violated the UN Security Council Resolution 2231 that has endorsed the deal.
The court could take months to give its opinion on this stage of the legal battle, while a final verdict could take years.