Hamas released a statement mourning Nasrallah's death while condemning Israel's bombardment of densely populated areas in Lebanon. 

"We mourn with all meanings of patience and acceptance His Eminence Sayyed Hassan Nasrallah and his brothers, and we recall his biography and career full of sacrifices for the sake of liberating Jerusalem and the blessed Al-Aqsa Mosque and the honourable positions supporting our Palestinian people, our valiant resistance and our legitimate rights," the statement said. 

The group offered "condolences and solidarity with the brothers in Hezbollah and the Islamic Resistance in Lebanon," celebrating Nasrallah's contributions to the “heroic front" and his support in the fight against Israel's war on Gaza and the occupation of Palestine.

The statement also condemned "in the strongest terms" Israel's targeting of residential buildings in the southern suburbs of Beirut on Friday.

"We condemn in the strongest terms this barbaric Zionist aggression and targeting of residential buildings... and we consider it a cowardly terrorist act," the group said.

The Palestinian Islamic Jihad group mourned Nasrallah's death, saying: "While we feel the pain of separation and the bitterness of losing a prominent Arab and Islamic figure of resistance who paved the way for victory for the nation, we also take pride in his blessed legacy... We are fully confident that the martyrdom of Sayyed Hassan Nasrallah will enhance the strength, resilience, and determination of the resistance in Lebanon, Palestine, and the region."

On Saturday, Iran's Supreme Leader Ayatollah Ali Khamenei condemned Israel's "short-sighted and foolish policies".

"The massacre of the defenceless people in Lebanon once again revealed the ferocity of the Zionist rabid dog to everyone, and proved the short-sighted and stupid policy of the leaders of the usurping regime," Khamenei said in a statement.

He added: "The Zionist regime had failed to learn from its year-long criminal war in Gaza and was now repeating the same mistakes in Lebanon."

Turkish President Recep Tayyip Erdogan said Israel was committing a "genocide" in Lebanon after Nasrallah was confirmed among hundreds killed in Israeli strikes this week.

"Lebanon and the Lebanese people are the latest target of a policy of genocide, occupation and invasion carried out by Israel since 7 October," Erdogan said on X.

Iraqi Prime Minister Mohammed Shia' Al-Sudani called for a three-day national mourning period across Iraq in tribute to Nasrallah's martyrdom in the "unjust Zionist aggression."

Sayyed Muqtada Al-Sadr, leader of Iraq's Shia National Movement, mourned Nasrallah in a tweet on X: "Farewell, O companion of resistance and defiance. We ask God to unite all resistors at the side of the Messenger of God, his successor Imam Ali, and his grandson Imam Hussein, peace be upon them." Sayyed Muqtada Al-Sadr also declared three days of mourning in Iraq.

The Iraqi Parliament announced it would organize a solidarity event with the Lebanese people against the "Zionist aggression."

Hezbollah ally Syria on Saturday condemned Israel's killing of the Lebanese group's chief.

"The Zionist entity (Israel) confirms through this despicable aggression, once again... its barbarism and wanton disregard for all international standards and laws," said a foreign ministry statement carried by state news agency SANA.

Lebanon's former Progressive Socialist Party leader Walid Jumblatt said on X: "Sayyed Hassan Nasrallah and his comrades have joined the long caravan of martyrs on the road to Palestine... I offer my condolences to Hezbollah and its supporters, and I salute the souls of the innocent civilians."

The Progressive Socialist Party issued the following statement: "The Progressive Socialist Party and its leadership extend their heartfelt condolences to the leadership and supporters of Hezbollah for the martyrdom of Secretary-General Sayyed Hassan Nasrallah and his fellow martyrs in a condemned assassination crime committed by the Israeli enemy, as well as for all civilian martyrs."

Lebanese Shia Amal Movement's presidency issued a statement mourning Nasrallah: "We mourn to our nation in Lebanon and the free people in the Arab and Islamic worlds a man among the truthful who feared no blame in defending truth and justice."

"In defence of truth, justice, freedom, and the liberation of the land and humanity in Lebanon and Palestine, and for the oppressed on the earth and those deprived of their land and rights, we honour the Secretary-General of Hezbollah, Sayyed Hassan Nasrallah."

Former Lebanese Defense Minister Yaacoub Sarraf said on X: "With hearts full of sorrow strengthened by faith, we bid you farewell, O faithful promise... You will leave a void that will resonate with your words through the air... And we will continue..."

The president of the Lebanese Democratic Party, Talal Arslan, said on X: "The beloved brother, a symbol of resistance and resistance fighters in the modern era, has passed away, leaving behind a legacy of pride, dignity, and resistance. This is not the time for sorrow or tears; it is time to rise, continue the journey, and endure... May God have mercy on Sayyed Hassan Nasrallah and all the martyrs. My heartfelt condolences to the brothers in the party leadership, his esteemed family, and all Lebanese."