US Secretary of State Antony Blinken landed in Saudi Arabia Wednesday as part of a regional tour to discuss efforts to secure a Gaza truce that includes a stop in Israel.

The US top diplomat touched down in Jeddah where he was expected to meet Saudi Crown Prince Mohammed bin Salman, said an AFP journalist on board.

The kingdom marks the first stop on Blinken's sixth Middle East tour since the Israel-Hamas war started on October 7.

Blinken is due to travel on Thursday to Egypt, which borders Gaza and has been involved in previous mediation efforts.

The following day he will head to Israel in a previously unscheduled visit that comes amid strained ties between US President Joe Biden and Israeli Prime Minister Benjamin Netanyahu.

State Department spokesman Matthew Miller announced the Israel visit as Blinken landed in Saudi Arabia.

The top diplomat will discuss with Israeli officials "the ongoing negotiations to secure the release of all hostages" and efforts to boost aid deliveries to Gaza, Miller said.

Blinken will also "discuss the need to ensure the defeat of Hamas, including in Rafah, in a way that protects the civilian population... and advances Israel's overall security," according to the spokesman.

Washington has supported Israel with billions of dollars in military aid since the October 7 Hamas attack, but has become increasingly frustrated by its ally's failure to curb civilian deaths or let in vital aid.

Another major area of concern for the US has been the fate of Rafah in the far south of the Gaza Strip.

Biden has put pressure on Netanyahu to pull back from a threatened full-scale ground operation on the tiny area which hosts around 1.5 million people, most of them displaced from elsewhere in the territory.

In Jeddah and Cairo, Blinken will discuss efforts to reach an "immediate ceasefire agreement that secures the release of all remaining hostages," Miller had said on Tuesday.

Blinken will also discuss "post-conflict planning for Gaza" with Saudi and Egyptian officials, Miller said.

He will discuss "a political path for the Palestinian people with security assurances with Israel, and an architecture for lasting peace and security in the region," the spokesman added.

On Tuesday, Blinken said everyone in Gaza was now suffering "severe levels of acute food insecurity".

"That's the first time an entire population has been so classified," he said during a visit to the Philippines.

The United States is also striving to broker an eventual normalisation agreement between Saudi Arabia and Israel, which would entail American security guarantees for the kingdom, Blinken's entourage told AFP.