European Commission president Ursula von der Leyen has described the Hamas attacks in Israel as "an ancient evil".
Addressing the weekly meeting of the 27 EU Commissioners, Ms von der Leyen said humanitarian support for the Palestinian people was "not in question" but that financial assistance had to be "carefully reviewed".
Israel's ambassador to the EU Haim Regev attended the meeting, during which a minute’s silence for the victims of the incursions was observed.
Ms von der Leyen said: "Hundreds of innocent people were murdered in cold blood. Hamas terrorists killed women and children in their homes.
"They hunted hundreds of young men and women who were celebrating life and music.
"They took hostage hundreds of innocents, whose fate is still unknown.
"These innocents were killed for one single reason. For being Jewish and living in the State of Israel.
"It is an ancient evil, which reminds us of the darkest past and shocks all of us to the core.
"We have to be clear in defining this kind of horror.
"It is terrorism. And it is an act of war."
She said Europe stood with Israel and its right to defend itself.
Hamas’s actions were completely unjustified, she said.
"There can be no justification for Hamas' act of terror.
"This has nothing to do with the legitimate aspirations of the Palestinian people.
"The horror that Hamas has unleashed will bring more suffering upon innocent Palestinians.
"Only Hamas is responsible for its actions."
Blinken to travel to Israel, as US military aid arrives
The Israeli army has said a first plane carrying additional US armaments has arrived in the country, ahead of the arrival of US Secretary of State Antony Blinken.
Mr Blinken is travelling to Israel later today after being sent by President Joe Biden, to deliver "a message of solidarity and support," US State Department spokesperson Matthew Miller said.
Last night, Mr Biden, described the attack on Israel by Hamas as "an act of sheer evil", and promised Israel the full support of his government.
He said Washington was rushing additional military assistance to Israel, including ammunition and interceptors to replenish the Iron Dome aerial defence system.
Mr Biden called for Israel to follow the "law of war" in its response.
US National Security adviser Jake Sullivan said Washington was talking also with Israel and Egypt about the idea of creating a safe passage for civilians out of Gaza.
Countries including Fiji, South Korea, Denmark, the Czech Republic and Canada scrambled to evacuate citizens, many stranded after major airlines cancelled flights.
Read More:
More than 260,000 people displaced in Gaza - UN
Who is Mohammed Deif? The man behind the Hamas attack
What we know about Israel's war with Hamas
Meanwhile, the US House of Representatives will meet to try to elect a new speaker.
Without a speaker, the US government cannot spend money to send aid Israel or Ukraine.
Last week's ousting of speaker of the House, Kevin McCarthy, by a faction of his own Republican Party, had immediate consequences for US funding of the war in Ukraine.
But the absence of a speaker means the house cannot vote new funds to support Israel either, despite promises by Mr Biden yesterday of more military and civil aid for Israel.
House Republicans, who have a five-seat majority, will meet later to try and agree a single candidate to stand for speaker, fully aware that the events of the last few days pile pressure on them to move quickly.
Mr Sullivan said the Biden Administration will seek a funding package for Israel that will be tied to aid for Ukraine.
The US is also without an ambassador to Israel, as Congress has not yet ratified President Biden's nominee.
Additional reporting: Sean Whelan/Reuters
