Mr Sunak will promise to intensify British efforts to work towards a two-state solution for Israel and Palestine.
“The UK wrote the original UN resolutions setting out a two-state solution. We’ve argued for it for decades. But now we must help make it a reality,” he will say.
“So, to the UK’s friends across the region and to our communities in this country, I pledge to redouble British efforts to this end.”
Claiming to represent a change from his Conservative predecessors, he will pledge to leave behind “past dogmas, assumptions and structures” in dealing with other nations, Downing Street said.
In a major foreign policy speech on Monday, Mr Sunak will tell international dignitaries and business leaders: “In these dangerous times, we’re not just defending a better vision of the future against those who would destroy it, we’re marshalling our expertise, our people and our alliances to bring that future into being.
“So, we’ll continue to stand up for what is right … and show that our values will prevail.”
Calling 2023 “one of the most significant years” for UK foreign policy in recent times, he will talk of the signing of the Windsor Framework with the EU, the update of British foreign and security policy and the announcement of plans for a new generation of nuclear-powered submarines under the Aukus partnership with the US and Australia.
Britain also struck migration deals with France, Italy and Albania, confirmed its accession to a major Indo-Pacific trade bloc and hosted an international summit on artificial intelligence safety.
The Windsor Framework trading arrangements were regarded as a key step in improving post-Brexit relations, after the more combative approaches taken by Mr Sunak’s predecessors, Boris Johnson and Liz Truss.
Rishi Sunak's first year as Prime Minister – in pictures
In his speech at the annual Lord Mayor’s Banquet in London’s Guildhall, Mr Sunak will say: “These treaties and alliances speak to something deeper: our willingness to act, to shape the world, not be shaped by it, wherever there’s a challenge, wherever there’s a threat, wherever we can promote peace and security.”
He will say that while Britain is pragmatic in its foreign policy approach, it is a time for “moral clarity”, noting its support for Kyiv in its struggle against Russia’s invasion and humanitarian support for civilians in Gaza amid the Israel-Gaza war.
“We’re hard-headed about what’s necessary for our interests and security. But Britain’s realism has always had values and this is a moment for moral clarity,” he will say.”
He is expected to say that Britain will never “lose patience” in backing Ukraine, calling Russian President Vladimir Putin’s invasion a “self-inflicted, strategic calamity” that he “cannot win”.
Mr Sunak faces calls to sack his Home Secretary Suella Braverman after she was accused of inflaming tensions over a pro-Palestinian march in London.