Thousands of Iranians took part in state-sponsored marches on Saturday to protest against the deaths of children and other civilians in the Gaza war.
Iran Revolutionary Guards (IRGC) Commander Hossein Salam said Israel was going towards its doom in a war of attrition.
"Palestine stands on the path of a war of attrition...Israel will face a definitive defeat and end up in the dustbin of history," Salami told a rally in the capital, Tehran, which was aired live on state TV.
"The battle is not over. The Islamic world will do whatever it has to do. There are still great (unused) capacities left," Salami said, without referring to any possible moves by Iran to join the conflict, according to Reuters.
Salami stated that the al-Aqsa Flood operation demonstrated that foreign aid and governments such as the US cannot save Israel from collapse because before they arrive to the rescue, Muslims and Palestinians can end this entity, according to the official Iranian News Agency (IRNA).
State television showed some protesters carrying bundled white shrouds symbolizing the children killed in Gaza during the nationwide marches held ahead of World Children's Day on Monday.
Tensions in the region have flared since a deadly attack by Iran-backed Hamas militants who burst through the border from Gaza into Israel on Oct. 7, killing some 1,200 people and taking around 240 hostages, including children, according to Israeli tallies.
On Saturday, the Iranian Ministry of Foreign Affairs appealed to the international community to help stop the "killing machine and organized terrorism of the Zionist regime against the Palestinian people and hold Zionist criminals accountable to justice and international law."