A large-scale Israeli operation in northern Gaza has killed and wounded dozens of people and threatens to shut down three hospitals over a year into the war with Hamas, Palestinian officials and residents said Wednesday.

Heavy fighting is underway in Jabaliya, where Israeli forces carried out several major operations over the course of the war and then returned as militants regroup. The entire north, including Gaza City, has suffered heavy destruction and has been largely isolated by Israeli forces since late last year.

Iranian Foreign Minister Abbas Araghchi travelled to Saudi Arabia on Wednesday for talks that were expected to cover efforts to end fighting between the Israeli military and Iran-backed groups in Gaza and Lebanon.

"I hope that these consultations can lead to better conditions for Palestine and Lebanon and establish peace in the region," Araghchi told Iranian state television upon his arrival in Riyadh.

U.S. President Joe Biden is expected to hold a crucial phone call on Wednesday morning with Israeli Prime Minister Benjamin Netanyahu about Israel's plans to strike Iran, three U.S. officials told U.S. news portal Axios.

The call would be the first between Biden and Netanyahu in two tense months, and comes as Israel considers major attacks that could significantly escalate its regional war.

British Foreign Secretary David Lammy warned on Wednesday that countries "must not waver" as they work towards ceasefires in Gaza and Lebanon, as he visited two regional allies.

Lammy, who will hold talks with leaders in Bahrain and Jordan and meet UK armed forces personnel currently stationed in the Middle East, called the situation there "incredibly dangerous."

Palestinian officials say Israeli strikes in central and northern Gaza killed at least 18 people, including five children and two women.

Two strikes hit tents for displaced people in the urban Nuseirat and Bureij refugee camps in central Gaza early Wednesday. The bodies of nine people, including three children, were brought to the Al-Aqsa Martyrs Hospital in the nearby town of Deir al-Balah. An Associated Press journalist saw the bodies at the morgue.

Israeli Defense Minister Yoav Gallant has postponed a trip to the United States scheduled for this week, delaying a planned meeting with his U.S. counterpart Lloyd Austin, the Pentagon said.

A war monitor said four people, including two non-Syrians, were killed in an Israeli air strike Tuesday targeting a building in the Syrian capital used by Iran's Revolutionary Guards for meetings with Hezbollah.

"Israel targeted a building frequented by senior Revolutionary Guards and Hezbollah operatives, as well as a car parked in front of the building... killing four people," the Britain-based Syrian Observatory for Human Rights said.

Palestinians say heavy fighting is underway in northern Gaza, where Israel has ordered another wholesale evacuation and launched a ground operation a year into the war with Hamas.

At least 15 people, including two women and four children, were killed Tuesday in the fighting in Jabaliya, the nearby Kamal Adwan Hospital said.

The Biden administration has in recent weeks grown “increasingly distrustful” of what the Israeli government says about its military and diplomatic plans in the multi-front war it is fighting, four U.S. officials told U.S. news portal Axios.

Israeli Prime Minister Benjamin Netanyahu said Monday that Israel was fighting a “war of resurrection” and would continue until achieving its goals, as Israelis marked the anniversary of the Hamas attack.

“This is the war of our existence — the ‘war of resurrection’. This is what I would like to officially call the war,” Netanyahu said during a Cabinet meeting.