At hearings last year, the United States raised five objections to the court's jurisdiction and the admissibility of the case, which Iran filed in 2016. On Wednesday, the United Nations' highest court upheld one U.S. objection to its jurisdiction, but it rejected another and said that the third objection should be discussed at a later stage in the case. The judges also rejected two U.S. objections to the admissibility of the case.
The case will likely take months or years to complete.
Iran's supreme leader says negotiations with the U.S. "will bring nothing but material and spiritual harm" — remarks that come ahead of an American-led meeting on the Mideast in Warsaw.
The comments from Ayatollah Ali Khamenei are part of a seven-page statement that was read out word-for-word on Iranian state television on Wednesday.
Currently, tensions between Iran and the U.S. are high after President Donald Trump pulled America out of the nuclear deal last year.
Khamenei says: "About the United States, the resolution of any issues is not imaginable and negotiations with it will bring nothing but material and spiritual harm."
The Warsaw summit, which starts Wednesday, was initially pegged to focus entirely on Iran. However, the U.S. subsequently made it about the broader Middle East, to boost participation.