In a departure from the tentative reprimands of his predecessor, former president Joe Biden, Trump and his top diplomat have declared themselves resolutely behind Netanyahu's objectives, whether over Israel's war in Gaza or the threat from Iran.

Rubio called the Islamic republic the "single greatest source of instability in the region".

"Behind every terrorist group, behind every act of violence, behind every destabilising activity, behind everything that threatens peace and stability for the millions of people who call this region home is Iran. And by Iran, I mean the ayatollahs," the secretary of state said alongside Netanyahu.

"Hamas cannot continue as a military or government force... It must be eliminated. It must be eradicated," Rubio added, echoing the Israeli prime minister's repeated war aim of destroying the militant group following its unprecedented October 7 attack on Israel, which started the war in Gaza.

Netanyahu said, as he did during a meeting with the American president during a visit to Washington earlier this month, that Israel had never had a better friend than Donald Trump.

In apparent evidence of this, the Israeli army announced on Sunday the overnight delivery to Israel of a shipment of "heavy" US bombs suspended by the Biden administration but unblocked by Trump a few days after he returned to power on January 20.

Rubio, who appeared at times tense during the first leg of his first Middle East visit, repeated pledges of support to Israel and its people, for whom he said the United States had "tremendous love and respect".

The Secretary of State will travel on to Saudi Arabia on Monday and then to the United Arab Emirates as part of his tour.

Change in tone 

Trump has outlined plans for a US takeover of Gaza and the displacement of its 2.4 million inhabitants to Egypt and Jordan, triggering widespread international condemnation and delight from the Israeli government.

Rubio called the initiative "something that, frankly, took courage and vision".

Rubio also held talks with Israeli President Isaac Herzog and Foreign Minister Gideon Saar, during which they warmly welcomed the renewed support of the United States.

The Biden administration had also displayed "unwavering" support for Israel, including participating in its defence during two missile attacks by Iran, but it also had complicated and tense relations with Netanyahu over his prosecution of the war in Gaza.

The tone has now completely changed.

The US Secretary of State also visited the Yad Vashem Holocaust memorial in Jerusalem, where he denounced the rise of anti-Semitism as an "ancient poison" that had re-emerged in "this new century".

"It hides behind geopolitics. It embeds itself in international organisations, the curriculums of our colleges and universities," Rubio said, before laying a wreath and, as is the Jewish tradition, a stone at a memorial to the victims of the Nazi concentration camps.