Representatives of South Africa opened the second day of hearings at the ICJ, also known as the World Court, in the Hague.
The hearing follows a request by the U.N. General Assembly for an advisory, or non-binding, opinion on the occupation in 2022. More than 50 states will present arguments until February 26.
On Monday, Palestinian representatives asked the U.N.'s highest court to declare Israel's occupation of their territory illegal, also saying the advisory opinion could contribute to a two-state solution and lasting peace.
Israel is not attending the hearings but sent a written statement, saying an advisory opinion would be harmful to achieving a negotiated settlement with the Palestinians.
"A clear legal characterization of the nature of Israel's regime over the Palestinian people can only assist in remedying the ongoing delay and achieving a just settlement," Vusimuzi Madonsela, South Africa's ambassador to the Netherlands told the judges.
The latest surge of violence in Gaza, instigated by the October 7 attacks in Israel by Hamas, has complicated already deeply rooted grievances in the Middle East. The fighting between the rival sides has also damaged efforts towards finding a path to peace.
The ICJ's 15-judge panel has been asked to review Israel's "occupation, settlement and annexation ... including measures aimed at altering the demographic composition, character and status of the Holy City of Jerusalem, and from its adoption of related discriminatory legislation and measures."
The judges are expected to take roughly six months to issue an opinion on the request, which also asks them to consider the legal status of the occupation and its consequences.