US president Donald Trump has said Israel's Arab neighbours are realising they share a "common cause" with Israel over the threat from Iran.

Trump is urging the US and Israel to boost cooperation against common threats, and declared that Iran should never be allowed to have a nuclear weapon.

He said Iran — Israel's chief enemy in the Middle East - must also cease funding, training and supplying weapons to terrorist groups and militias.

Speaking during his first visit to Israel as US president, Trump said there is strong consensus on these issues among the world's nations, including many in the Muslim world.

Trump also thanked Israel's leaders for being committed to achieving peace between Israelis and Palestinians, and he will meet with Palestine's president Mahmoud Abbas as part of the visit.

Arriving directly from Riyadh, Saudi Arabia, Trump expressed his hope for cooperation among US allies in the Middle East.

His second stop on his nine-day tour aims to test the waters for reviving the dormant Israeli-Palestinian peace process.

Trump, who had previously suggested that it would be easier than anticipated to solve the conflict which has vexed his predecessors for decades, said conditions are right in both Israel and the Arab world to strike what he has called "the ultimate deal".

Upon arrival in Tel Aviv, Trump said: "We have before us a rare opportunity to bring security and stability and peace to this region and to its people."

Israeli prime minister Benjamin Netanyahu called Trump "a true friend" to Israel and expressed optimism about the president's role in the Middle East peace process.

Trump's first stop was a meeting in Jerusalem with Israeli president Reuven Rivlin. In a statement following the meeting, Trump addressed his meetings the previous day with Arab and Muslim leaders in Saudi Arabia, and said that there is growing realisation that they share a "common cause with you" in their determination to defeat extremism and deter "the threat posed by Iran".

However, obstacles have emerged which may complicate the relationship between the White House and the Knesset.

The US leader faced questions about revelations that he disclosed sensitive Israeli intelligence regarding Daesh to Russian officials, and concerns over the new 110 billion dollar (£84 billion) arms deal he announced with the Saudis.

Speaking alongside Israel's prime minister Benjamin Netanyahu, Trump claimed he never mentioned "the word or the name Israel".

US officials said the information originated from Israel.

Netanyahu added that US-Israeli intelligence co-operation is "terrific".

Trump said the story is another one the news media has gotten wrong.

White House aides have also tried to play down expectations for significant progress on the peace process during Trump's visit, casting it as "symbolic".

Tillerson referred to the visit as "a moment in time" and suggested that the US would take a more active role in the future in brokering a deal if both sides make serious commitments.

Trump, whose unorthodox approach has spurred some hope on both sides of the Israeli-Palestinian conflict, has done no such managing of expectations.

After hosting Abbas at the White House in March, Trump boldly stated that achieving peace is "something that I think is, frankly, maybe not as difficult as people have thought over the years".

"But we need two willing parties," he continued.

"We believe Israel is willing. We believe you're willing. And if you both are willing, we're going to make a deal."

Trump made one symbolic gesture in bridging the gap between Israel and the Arab world. His flight on Air Force One was believed to be the first direct flight between Saudi Arabia and Israel, nations which do not have diplomatic relations.

Netanyahu said he hoped an Israeli prime minister could soon make the same flight.

While Israeli officials cheered Trump's election, some are now wary of the tougher line he has taken on settlements — urging restraint, but not calling for a full halt to construction.

Trump has also retreated from a campaign pledge to move the US Embassy in Israel from Tel Aviv to Jerusalem, bending to the same diplomatic and security concerns as other presidents who have made similar promises.

Palestinians, who viewed Trump's victory with some trepidation, are said to have been pleasantly surprised by his openness during a recent meeting with Mr Abbas in Washington.

On the eve of Trump's visit, an Israeli official said Netanyahu's cabinet has approved confidence building measures with the Palestinians, including allowing building in a West Bank area.

The package includes building permits for Palestinians in Area C, which has largely been off limits to Palestinian development until now.