Washington: US President Joe Biden has said the US stands with Israel in the face of terrorist assaults by Hamas and will make sure the country has the help its citizens need.

"Today, the people of Israel are under attack orchestrated by the terrorist organization, Hamas. In this moment of tragedy, I want to say to them and to the world and to terrorists everywhere that the United States stands with Israel. We will not ever fail to have their back, we'll make sure that they have the help their citizens need and they can continue to defend themselves," the US President said on Saturday.

A major upheaval took place in the Middle East on Saturday, when the Hamas terror group launched a "surprise attack", firing a barrage of rockets into southern and central Israel.

According to the latest developments, more than 200 people have been killed, at least 1,104 people are injured and several Israelis have been held as hostages in Gaza, the Times of Israel reported citing officials.

Biden said the world has seen appalling images, thousands of rockets in the space of hours raining down on Israeli cities.

"I spoke with Prime Minister Netanyahu this morning I told him the United States stands with the people of Israel in the face of these terrorist assaults. Israel has the right to defend itself and its people. There's never a justification for terrorist attacks and my administration's support for Israel's security is rock solid and unwavering," Biden said.

The US President said he has directed his team to remain in constant contact with leaders throughout the region including Egypt, Turkey, Saudi Arabia, Jordan, Oman the UAE as well as European partners and the Palestinian Authority.

He said: "It's also a terrible strategy on a human level, it's hurting innocent people seeing the lives that have been broken by this, the families torn apart it's heart-breaking and Jill and I are praying for those families who've been impacted by this violence we grieve with those who've lost their loved ones lost a piece of their soul."

The US President further said he hopes for a swift recovery for many who have been wounded but "we're going to remain in close touch with Prime Minister. I personally am going to remain in close contact with Prime Minister Netanyahu as this situation continues to develop and let there be no mistake the United States stands with the state of Israel just as we have from the moment the United States became the first nation to recognize Israel, 11 minutes after its founding 75 years ago," he said.

At about 6:30 am (local time), a barrage of rocket fire began from Gaza into Israel, hitting several cities including Tel Aviv, Rehovot, Gedera and Ashkelon.

This was followed by several Hamas terrorists entering Israel from the Gaza Strip and taking over Israeli towns.

Secretary of State Antony J. Blinken on Saturday spoke with Israeli President Isaac Herzog and Foreign Minister Eli Cohen. Secretary Blinken reiterated his condolences for the victims of the terrorist attacks against Israel and condemned those attacks in the strongest terms.

The Secretary reaffirmed the United States' solidarity with the government and people of Israel. Secretary Blinken also discussed measures to bolster Israel's security. The Secretary underscored the United States' unwavering support for Israel's right to defend itself.

Meanwhile, US Secretary of Defence Lloyd Austin said: "I spoke with Israeli Minister of Defence Gallant to convey my condolences for this appalling terrorist attack by Hamas on Israel. I reaffirmed US commitment to Israel's security, and will stay in close touch with Minister Gallant in the coming days and weeks to ensure Israel has the support it needs."

US State Department spokesperson Mattew Miller also reacted to the attack, said: "The deal to bring US citizens home from Iran has nothing to do with the horrific attack on Israel. Not a penny has been spent, and when it is, it can only go for humanitarian needs like food and medicine. Anything to the contrary is false."

Former US President Donald Trump also reacted to the Hamas attack, said: "The Israeli attack was made because we are perceived as being weak and ineffective and with a really weak leader."

The United Nations Security Council (UNSC) will hold a closed-door session on the Middle East situation at 3 pm (US local time) on Sunday, as per the website of the UN.