Speaking to the National Congress, Boric decried the "catastrophic humanitarian situation" in
Gaza and called for "a firm response from the international community."
"Chile will become a party to and support the case that South Africa presented against Israel before the International Court of Justice in The Hague," Boric said.
The ICJ is considering South Africa's case, but in the interim has brought in "preliminary measures" ordering Israel do everything it could to prevent acts of genocide during its campaign against Hamas.
The top UN court last month ordered Israel to halt military operations in the southern Gaza city of Rafah, where displaced Palestinians are seeking safety from Israel's military offensive.
Before the Rafah offensive began, the United Nations said up to 1.4 million people were sheltering in the city.
Since then, one million have fled the area, the UN agency for Palestinian refugees, UNRWA, has said.
Chile has recognized Palestine as a state since 2011, and Boric has previously said the war in Gaza has "no justification" and is "unacceptable."
The Gaza war was sparked by Hamas's unprecedented October 7 attack, which resulted in the deaths of 1,189 people, mostly civilians, according to an AFP tally based on Israeli official figures.
Militants also took 252 hostages, 121 of whom remain in Gaza, including 37 the army says are dead.
Israel's retaliatory offensive has killed at least 36,379 people in Gaza, mostly civilians, according to the Hamas-run territory's health ministry.
