The death toll has risen after Hamas fired rockets into Israel from Gaza in a surprise attack and Israel declared war.

According to Israeli officials, at least 40 people have died in Israel and more than 700 people have been injured. The Palestinian Health Ministry said 160 people were killed in Gaza and over a 1,000 others were injured.

According to Al Jazeera, Israeli forces have surrounded a house in the Israeli settlement of Ofakim and negotiations are underway with Palestinian fighters who are allegedly holding hostages. According to the Jerusalem Post, dozens of hostages are being by Hamas in the Kibbutz Be’eru in southern Israel.

President Joe Biden was briefed Saturday "on the appalling Hamas terrorist attacks in Israel," according to the White House.

"Senior national security officials briefed the President this morning on the appalling Hamas terrorist attacks in Israel. The President will continue to receive updates and White House officials remain in close contact with Israeli partners," the White House said in a statement.

-ABC News' Fritz Farrow

U.S. Defense Secretary Lloyd Austin released a statement saying he is "closely monitoring" the situation in Israel and extended his condolences to the families of those who have lost their lives.

"Over the coming days the Department of Defense will work to ensure that Israel has what it needs to defend itself and protect civilians from indiscriminate violence and terrorism," Austin said.

Separately, a U.S. defense official said that Austin had a call with his team Saturday morning, including U.S. Centcom Commander Gen. Eric Kurilla. Israel falls under Centcom’s area of responsibility.

-ABC News' Luis Martinez

Israeli Prime Minister Benjamin Netanyahu made a video statement on social media, saying simply, “We are at war. We will win," in his first comments, made in Hebrew, after the attack.

"Citizens of Israel, we are at war, not in an operation or in rounds, but at war. This morning, Hamas launched a murderous surprise attack against the State of Israel and its citizens. We have been in this since the early morning hours. I convened the heads of the security establishment and ordered – first of all – to clear out the communities that have been infiltrated by terrorists," Netanyahu said. "This currently is being carried out. At the same time, I have ordered an extensive mobilization of reserves and that we return fire of a magnitude that the enemy has not known. The enemy will pay an unprecedented price. In the meantime, I call on the citizens of Israel to strictly adhere to the directives of the IDF and Home Front Command. We are at war and we will win it."

A State Department official said Monday night that the department has offered 4,000 American citizens and their immediate family members help to depart Israel via government-organized transportation since Friday.

“Since Oct. 13, we have augmented the limited commercial flight availability by offering more than 4,000 seats on U.S. government-chartered transport by air and sea to U.S. citizens and their immediate family members,” one official said. “We have communicated the availability of departure assistance options for U.S. citizens via targeted, individualized messaging as well as via broad public messaging.”

Departing flights, though, were not nearly at capacity, the official said.

“The departure options we have offered have generally departed at half capacity or less. Nearly 1,000 U.S. citizens and their immediate family members have departed on U.S. government-chartered transport,” an official said.

The official added that 3,000 other American citizens have told the State Department that they were able to leave Israel and the West Bank on their own.

-ABC News’ Shannon Crawford