Palestinian President Mahmoud Abbas has declared three days of mourning after a "hospital massacre" in Gaza, a strike that Hamas officials blamed on Israel and say killed at least 500 people.
Mr Abbas announced "public mourning for three days and flags flown at half-mast for the martyrs of the Baptist hospital massacre and all our people's martyrs", the official Palestinian news agency Wafa said.
The Israeli military has denied responsibility, and has blamed a failed rocket launch by a Palestinian militant group.
A White House Official said US President Joe Biden sent his condolences for the innocent lives lost in the strike, and wished a speedy recovery to those who were wounded.
Jordan has cancelled a summit it was to host in Amman with Mr Biden and the Egyptian and Palestinian leaders to discuss the situation in Gaza, the country's foreign minister, Ayman Safadi has said.
Mr Biden was expected to meet the Arab leaders following a solidarity visit to Israel.
Jordan's foreign ministry issued a statement strongly condemning the attack.
The statement stressed the need to provide international protection for the Palestinian people and called for efforts to stop the war from raging in Gaza.
Turkey's foreign ministry condemned in the strongest terms the "barbaric attack" on the hospital.
In a statement it said: "We are deeply indignant that hundreds of Palestinians lost their lives and many more were injured as a result of the targeting of a hospital in Gaza today, and we condemn these barbaric attacks in the strongest terms."
Meanwhile, Canadian Prime Minister Justin Trudeau said the strike on the hospital in Gaza was "horrific and absolutely unacceptable".
Mr Trudeau told reporters that "it's not acceptable to hit a hospital".
Egypt also denounced the air strike in the "strongest terms", saying the international community must urgently intervene to stop such violations, according to a foreign ministry statement released late on Tuesday.
State media reported that Iranian officials described the attack as "heinous" and a "savage war crime", while Qatar's foreign ministry condemned what it said was "a brutal massacre" and "a heinous crime against defenceless civilians".
In a statement the Gulf state called the attack on Ahli Arab Hospital a "blatant violation of the provisions of international law" and a "dangerous escalation in the course of the confrontations".
EU Council chief Charles Michel said that targeting civilian infrastructure in Gaza breaks international law.
"We got this information when we were together during this virtual meeting with the leaders. It seems to be to be confirmed and an attack against a civilian infrastructure is not in line with international law," Michel said after a video conference of EU leaders.
Israel's military has denied responsibility for the attack, saying military intelligence suggested the hospital was hit by a failed rocket launch by Hamas.
"An analysis of IDF operational systems indicates that a barrage of rockets was fired by terrorists in Gaza, passing in close proximity to the Al Ahli hospital in Gaza at the time it was hit," a spokesperson for the Israel Defense Forces said in a statement.
Speaking to RTÉ News, Taoiseach Leo Varadkar repeated his insistence that "civilian infrastructure" must not be targeted in Gaza.
"I've heard some initial reports of a strike on a hospital in Gaza. These are early reports, they're very concerning reports.
"We don't have the full information yet, but I think it emphasises very much our view that civilian infrastructure should not be targeted."
The Taoiseach said: "There is evidence Hamas uses civilian infrastructure as a cover for its operations, but that doesn't justify operations that may cause the deaths of hundreds of civilians."
ActionAid Ireland said the bombing was an "horrific breach of humanitarian law".
CEO, Karol Balfe, said: "Hospitals in Gaza are seen as a place of safety and refuge for many civilians seeking shelter during continuous bombardment. It is imperative that the international community unites to hold those responsible accountable. We cannot be clearer; civilians must be protected under humanitarian law – they are not a target."
