U.K. Prime Minister Keir Starmer arrived in Sharm el-Sheikh late Sunday to attend a summit with leaders from more than 20 countries on peace in Gaza and the broader Middle East.

The summit will be co-chaired by Egyptian President Abdel-Fattah el-Sissi and U.S. President Donald Trump, who is first expected to stop in Israel on Sunday morning.

It's a fragile moment with Israel and Hamas only in the early stages of implementing the first phase of the Trump agreement designed to bring a permanent end to the war sparked by the October 7, 2023, attack on Israel by Hamas-led militants.

The first phase of the ceasefire agreement calls for the release of the final 48 hostages held by Hamas, including about 20 believed to be alive; the release of hundreds of Palestinian prisoners held by Israel; a surge of humanitarian aid to Gaza; and a partial pullback by Israeli forces from Gaza’s main cities.

Israeli troops on Friday finished withdrawing from parts of Gaza, triggering a 72-hour countdown under the deal for Hamas to release the Israeli hostages, potentially while Trump is on the ground there.

He said he expected their return to be completed on Monday or Tuesday.

It is a tenuous truce and it is unclear whether the sides have reached any agreement on Gaza’s postwar governance, the territory's reconstruction and Israel’s demand that Hamas disarm.

Negotiations over those issues could break down, and Israel has hinted it may resume military operations if its demands are not met.