United Nations Secretary-General Antonio Guterres said on Tuesday he is "shocked" by the Israeli airstrikes in Gaza and has called for the ceasefire in Gaza to be respected.
Guterres, in a statement, called for humanitarian aid to resume for people in Gaza and for the hostages held by Hamas to be released unconditionally.
Israel launched airstrikes across the Gaza Strip early Tuesday, killing at least 413 Palestinians, including women and children, according to hospital officials. The surprise bombardment shattered a ceasefire in place since January and threatened to fully reignite the 17-month-old war.
Prime Minister Benjamin Netanyahu ordered the strikes after Hamas refused Israeli demands to change the ceasefire agreement. Officials said the operation was open-ended and was expected to expand. The White House said it had been consulted and voiced support for Israel's actions.
Saudi Arabia's foreign ministry said on Tuesday it denounces "in the strongest terms" Israel resuming strikes on Gaza, and called on the international community to step in to stop what it described as crimes against the Palestinians.
Also, Qatar's Prime Minister Sheikh Mohammed bin Abdulrahman Al Thani on Tuesday demanded immediate international action to compel Israel to implement an immediate ceasefire, abide by the Gaza ceasefire agreement and return to negotiations.
France called for an immediate halt to the violence, the French Foreign Affairs ministry said in a statement.
Türkiye said Israel's attacks on Gaza amounted to a "new phase in its policy of genocide" against Palestinians and urged the international community to take a determined stance to ensure a ceasefire is upheld and humanitarian aid is delivered.
In a statement, the Turkish Foreign Ministry added it was unacceptable for Israel to cause a "new cycle of violence" in the region, adding the Israeli government's "hostile approach" threatened the future of the Middle East.
The Kremlin said it was concerned by what it called a large number of civilian casualties after Israel struck Gaza and hoped that peace would return.
"Undoubtedly, it's another deterioration in the situation (in Gaza) and another spiral of escalation that is causing our concern," Kremlin spokesman Dmitry Peskov told reporters.
"Especially concerning of course are the reports of major casualties among the civilian population," he added.
"We are monitoring the situation very closely and, of course, we are waiting for it to return to a peaceful course."
Australian Prime Minister Anthony Albanese called for the ceasefire to be maintained.
"There’s already been enormous suffering there, which is why we’re calling upon all parties to respect the ceasefire and hostage deal that was put in place," Albanese told reporters.
"We’ll continue to make representations. Australia will continue to stand up for peace and security in the region," he added.
The United Nations' Humanitarian Coordinator for the Occupied Palestinian Territory urged for the ceasefire in Gaza to be immediately reinstated.
"Waves of airstrikes occurred across the Gaza strip since the early hours of the morning ... This is unconscionable. A ceasefire must be reinstated immediately," Muhannad Hadi said in a statement.
The UN human rights chief said he was horrified by Israeli strikes on Gaza.
"I am horrified by last night's Israeli airstrikes and shelling in Gaza, which killed hundreds, according to the Ministry of Health in the strip. This will add tragedy onto tragedy," said High Commissioner Volker Turk in a statement.
"Israel's resort to yet more military force will only heap further misery upon a Palestinian population already suffering catastrophic conditions."
