The declaration was inked by Israeli Prime Minister Yair Lapid and Biden, who was making his first trip to the Middle East as president.

It commits the United States to "never to allow Iran to acquire a nuclear weapon", stating that it "is prepared to use all elements of its national power to ensure that outcome".

A landmark deal that imposed curbs on Iran's suspect nuclear programme in exchange for sanctions relief was torpedoed in 2018 by former US president Donald Trump. Efforts to revive the accord have stalled since March.

Asked on Thursday how long the US was prepared to give those efforts, Biden said "we're not going to wait forever" for a response from the Islamic republic.

Israel, which has the Middle East's sole but undeclared nuclear arsenal, is staunchly opposed to the deal with Iran, which has always denied seeking the bomb.

Lapid warned "words" and "diplomacy" were not enough to thwart Iran's alleged nuclear ambitions.

"The only thing that will stop Iran is knowing that if they continue to develop their nuclear programme the free world will use force," he said.

Iran's ultra-conservative President Ebrahim Raisi warned the US and its allies that his country "will not accept any crisis or insecurity in the region".

"Any mistake made in this region will be met with a harsh and regrettable response," Raisi said in televised remarks.

- Saudi oil -

Biden touched down in Israel on Wednesday, his 10th visit to the Jewish state since 1973, when he came as a newly elected senator.

He also held talks with Israeli President Isaac Herzog on Thursday and opposition leader Benjamin Netanyahu, whom Biden has known for four decades.

"I told him that the Iran deal is lousy. He knows my position," said a statement released after the meeting by Netanyahu, whose outspoken opposition to the deal soured Israel's relations with former president Barack Obama's administration, in which Biden served as vice president.

Biden heads to the occupied West Bank on Friday to meet Palestinian president Mahmud Abbas, before Air Force One makes the first publicly acknowledged direct flight from Israel to Saudi Arabia.

The US president said the journey itself "represents important progress", following Israel launching diplomatic ties in 2020 with Riyadh's Gulf neighbours the United Arab Emirates and Bahrain.

"Israel's integration in the region, Israel's peace with its neighbours, these are essential goals," Biden said.

A high-ranking official late Thursday said that Israel would have "no objection" to greenlighting Egypt handing over two strategic Red Sea islands to Saudi Arabia as a step towards normalisation.

Russia's invasion of Ukraine will be a top priority for the president's meetings with Arab leaders, with volatile oil prices due to be the focus of talks with Saudi officials in particular.

The president will seek to persuade Saudi Arabia to pump more oil in order to drive down prices, which have fuelled US inflation to the highest levels in decades.

- 'Israel wants peace' -

On Thursday, Biden reaffirmed Washington's policy of pressing for "a two-state solution for two people, both of whom have deep and ancient roots in this land."

But he made it clear he has no plans to reverse Trump's controversial decision to recognise Jerusalem as Israel's capital.

Lapid is serving as caretaker prime minister ahead of elections in November -- Israel's fifth vote in less than four years -- and is therefore not expected to launch new talks with Palestinians, but reasserted his personal support for Palestinian statehood.

"A two-state solution is a guarantee for a strong, democratic state of Israel, with the Jewish majority," he said.

A US official said the administration would announce during the visit "a significant funding package" for hospitals that serve Palestinians in Israeli-annexed east Jerusalem, which Palestinians claim as their future capital.

It will also announce measures towards providing 4G internet access in the West Bank and Israeli-blockaded Gaza Strip, the official said, addressing a persistent Palestinian frustration.

But long-term peace negotiations were not on this week's agenda.

"We are not going to come in with a top-down peace plan because we don't believe that would be the best approach," the official said.

At an anti-Biden protest in Ramallah, Palestine Liberation Organization executive Bassam Al-Salihi accused the US administration of buying into an Israeli tactic viewing "the Palestinian cause as an economic issue."