US President Donald Trump threatened Hamas on Tuesday with "FAST, FURIOUS & BRUTAL" force if it does not "do what is right" as he pushes for the next, more complex, stage of a Gaza ceasefire that has already been repeatedly tested.
Increasing the pressure on the Palestinian group, Trump said in a social media post that numerous US allies had said they would welcome the chance to go into Gaza and hit Hamas but he had told them and Israel "not yet".
Israel and Hamas have accused each other of repeated breaches of the truce since it was signed eight days ago, with flashes of violence and recriminations over the pace of returning hostage bodies, bringing in aid and opening borders.
US Vice President JD Vance, who arrived on Tuesday, was due to meet Israeli Prime Minister Benjamin Netanyahu on Wednesday for talks Israel said would focus on security challenges and political opportunities.
Those are expected to focus on Trump's 20-point ceasefire plan that will require moving beyond the existing, shaky ceasefire, to much more difficult steps including the disarmament of Hamas and a path towards a Palestinian state.
The trip follows Monday's talks between Netanyahu and US envoys Steven Witkoff and Trump's son-in-law Jared Kushner and comes as Hamas meets mediators in Cairo.
Israel is pressing for stronger assurances on Hamas disarming - a step to which the group has so far refused to commit - said a source briefed on the matter.
Hamas' Cairo talks, led by the group's exiled leader Khalil al-Hayya, are also looking at prospects for the next phase of the truce and post-war arrangements in Gaza as well as stabilizing the existing ceasefire.
The head of intelligence for key Gaza mediator Egypt met Netanyahu earlier on Tuesday to discuss advancing the ceasefire plan and other issues, Israel said. The intelligence chief, Hassan Mahmoud Rashad, will later meet Witkoff, Egyptian television reported.
Underscoring the fragility of the truce, Qatar, another of the mediators, on Tuesday accused Israel of "continuous violations". It and Turkey, which has used its role to bolster its regional position, have been key interlocutors with Hamas.
Trump's plan called for the establishment of a technocratic Palestinian committee overseen by an international board with Hamas taking no role in governance.
A Palestinian official close to the talks said Hamas encouraged the formation of such a committee to run Gaza without any of its representatives, but with the consent of the group as well as the Palestinian Authority and other factions.
Last week, senior Hamas official Mohammed Nazzal told Reuters the group expected to maintain a security role on the ground in Gaza during an undefined interim period.
Hamas last week battled rival gangs on the streets in Gaza and publicly executed men it accused of having collaborated with Israel. Trump condoned the killings, but the US military's Middle East command urged Hamas to stop violence "without delay".