Hosseini made the remarks in a meeting with Palestinian Ambassador to Iran Salah al-Zawawi on Monday.
Hosseini felicitated the victory of the Palestinian nation in the war with Israel, and said unity plays a pivotal role in continuation of such victories.
Al-Zawawi, for his part, appreciated Iran's all-out support for the innocent people of Gaza.
Israel triggered an 8-day fighting by assassinating the military chief of the ruling Hamas group on November 14 followed by dozens of airstrikes on Gaza.
In response, Palestinian groups fired over 1,500 missiles and rockets at Israel.
Palestinian resistance groups targeted Tel Aviv and areas near Jerusalem for the first time in the history of confrontations between the two sides, launching a rocket attack in a major escalation of hostilities as Israel pressed forward with relentless airstrikes on the Gaza Strip.
Israel called up thousands of reservists and massed troops along the border with Gaza, signaling a ground invasion of the densely populated seaside strip could be imminent.
But the attack on the Israeli settlement, along with an earlier strike on Zionists' capital Tel Aviv, frightened the Israeli regime, making it drop its aggression plans and ask for third party mediation.
Eventually, a Cairo-mediated ceasefire agreement, which took effect on Wednesday November 21, ended the Israeli attacks, which killed more than 165 Palestinians and injured about 1,269 others.
Based on figures, over 25% of the death toll during the recent war in the enclave pertained to innocent Gazan children.