The White House said Wednesday that President Joe Biden would limit physical contact during his Middle East tour, citing coronavirus concerns, as he landed in Israel ahead of a delicate trip to Saudi Arabia.

Biden, 79,  began his first regional visit as president by landing at Ben Gurion airport near the Israeli coastal city of Tel Aviv and he will fly to the Saudi city of Jeddah later this week.

But all eyes will be on his interaction with Saudi Crown Prince Mohammed bin Salman, who the CIA has said was likely behind the 2018 killing of dissident journalist Jamal Khashoggi, a Saudi national and US resident. 

The Khashoggi affair -- he was murdered and dismembered in Saudi's Istanbul consulate -- fed into Biden saying in his successful campaign for the US presidency in 2020 that the kingdom should be treated as a pariah state.

His administration has stepped substantially away from that stance in recent months, as it lobbies Riyadh to pump more oil to reduce highly elevated prices of this commodity, a major factor in a recent surge in US inflation to 40 year highs.

But in the weeks ahead of Biden's tour, the White House was coy about any direct interaction between the US president and the crown prince during the Saudi leg of his visit.

Images of Biden shaking Prince Mohammed's hand in Jeddah would likely draw intense media scrutiny.

Citing concerns about the spread of the coronavirus, Biden's press secretary Karine Jean-Pierre said "it's reasonable to expect (Biden) to take some additional precautions. 

"We're trying to minimise contact as much as possible," she told reporters on Air Force One.

"I wouldn't say there's a change" in health protocols, she replied when asked if the measures were aimed at preventing a handshake with Prince Mohammed. 

Biden refrained from shaking hands with Israeli dignitaries who greeted him on the tarmac at Israel's Ben Gurion airport on Wednesday.

He did hold brief, but close and mask-less, face-to-face discussions with Israeli President Isaac Herzog, Prime Minister Yair Lapid and alternate premier Naftali Bennett. They all exchanged fist bumps. 

Biden however did shake hands with an old acquaintance who greeted him at the airport -- former Israeli prime minister and current opposition leader Benjamin Netanyahu. 

Netanyahu had a fraught relationship with former US president Barack Obama's administration, in which Biden served as vice president, amid a bitter dispute over how to contain Iran's nuclear ambitions. 

According to Netanyahu's office, Biden told the ex-premier: "You know I love you," as they met on Wednesday.  

Biden, known for his warmth, was also seen shaking hands during an event with lawmakers at the White House just ahead of his trip.