The US president and fellow negotiators, Egypt, Qatar and Turkey, will sign off the peace plan in Sharm El Sheikh, joined by leaders from more than 20 countries.
The summit, co-hosted by the US leader and Egyptian president Abdel Fattah El-Sisi, comes as part of efforts to secure the fragile ceasefire between Israel and Hamas that has been holding since Friday.
President Donald Trump as he heads to the Middle East for a summit marking the ceasefire (Evan Vucci/AP)
Mr Trump, who will first travel to Israel to meet with hostage families and address parliament there, said he was “very excited about this moment in time” before Air Force One took off.
He said many in both Israel and Arab countries were “cheering” the agreement and that “everybody’s amazed and they’re thrilled and we’re going to have an amazing time”.
Speaking to reporters while in the air, Mr Trump deemed the conflict “over”, adding: “I think people are tired of it.”
He also said he hoped to one day visit Gaza, telling travelling reporters: “I’d like to put my feet on it, at least.”
Under the first phase of the agreement brokered by the US President, the remaining hostages held by Hamas are due to be returned to their families and Palestinian prisoners are to be released by Monday morning.
Sir Keir will urge those at the Sharm El Sheikh summit to build on the momentum to bring about the second phase of plans to end the conflict.
He is expected to heap praise on Mr Trump and the diplomatic efforts of the other negotiators, as well as commit the UK to playing a key role in rebuilding Gaza.
Sir Keir will say: “We stand determined to seize this opportunity to deliver a lasting peace and a stable, secure future for the whole region.
“Today is the first, crucial phase of ending this war and now we must deliver the second phase, in full.
“The UK will support the next stage of talks to ensure the full implementation of the peace plan, so that people on both sides can rebuild their lives in safety and security.”
National security adviser Jonathan Powell has been speaking to Mr Trump’s Middle East envoy Steve Witkoff almost daily, it is understood.
After the UK last month confirmed recognition of Palestinian statehood – without Hamas leadership – Sir Keir is understood to want to draw on the Northern Ireland peace process as talks move towards “decommissioning” Hamas.
A suggestion from one of his Cabinet ministers on Sunday that the UK played a “key role” in securing the Gaza ceasefire was roundly rejected by top US and Israeli figures, which could prove awkward for Sir Keir.
Foreign Secretary Yvette Cooper said the ceasefire will allow for humanitarian efforts in Gaza to be urgently scaled up (Charles McQuillan/PA)
US ambassador to Israel, Mike Huckabee, called Bridget Phillipson’s comments “delusional”, while Benjamin Netanyahu’s deputy foreign minister, Sharren Haskel, rejected her characterisation of the UK’s role.
Sir Keir will also announce a £20 million humanitarian aid package for Gaza as the UK is set to host a three-day conference on Gaza’s recovery and reconstruction.
Foreign Secretary Yvette Cooper said: “Gaza has been completely devastated. The ceasefire gives us the opportunity not just to urgently scale up humanitarian efforts but also to look to the future of Gaza’s recovery. Rubble must be cleared, infrastructure repaired, healthcare restored and homes rebuilt.”
The 20-point plan set out by the US President calls for Israel to maintain an open-ended military presence inside Gaza along its border with Israel.
Former prime minister Sir Tony Blair is said to be poised to join a ‘Board of Peace’ supervising the governance of Gaza (Victoria Jones/PA)
An international force, comprised largely of troops from Arab and Muslim countries, would be responsible for security inside the enclave.
The Israeli military has said it will continue to operate defensively from the roughly 50% of Gaza it still controls after pulling back to the agreed-upon lines.
There are no plans to send British troops to be part of the multinational force that will monitor the truce.
Meanwhile, former prime minister Sir Tony Blair, who was poised to potentially join a “Board of Peace” supervising governance of Gaza under the plans, met the deputy chief of the Palestinian Authority on Sunday.
