The US is looking into whether Israel breached the Gaza ceasefire deal by killing a senior Hamas leader at the weekend, President Donald Trump has said.
The Israeli army said it killed Raed Saad in a Gaza city air strike on Saturday that killed five other people and wounded 25, according to the enclave's health authorities.
It was the highest-profile assassination of a senior Hamas figure since a US-brokered ceasefire came into effect in Gaza in October.
When asked on Monday whether Israel had breached the truce by attacking the Hamas commander, Mr Trump told reporters: "We're gonna have to see, we're looking into that."
The US President also denied any rift between himself and Israel's Prime Minister Benjamin Netanyahu after the strike, saying they had a "very good relationship". The two leaders are expected to meet in the US on December 29 for talks on advancing the Gaza ceasefire plan.
Hamas confirmed the death of Mr Saad on Sunday and said its armed wing, Al Qassam Brigades, had appointed a new commander to succeed him.
"The Palestinian people are currently going through difficult times and suffering greatly ... with the martyrdom of more than 70,000 people, the latest of whom was the mujahid commander Raed Saad and his companions," said Hamas's Gaza leader Khalil Al Hayya in a televised speech.
A fragile ceasefire came into effect in Gaza on October 10, although Israel continues to carry out attacks, demolitions and night-time incursions across the truce withdrawal line. Israel has killed at least 390 Palestinians since the truce began, according to Gaza's health authorities.
The initial phase of Mr Trump's 20-point peace plan established the current ceasefire in Gaza. Phase one also included the release of all Israeli hostages in exchange for Palestinian detainees.
The second phase of the plan is expected to be more complicated as it deals with the future governance of the strip and the disarmament of Hamas, which the militant group has not agreed to.
It allows for an international stabilisation force to be stationed in Gaza to oversee the ceasefire agreement and reconstruction of the war-torn enclave.
Last month, the UN Security Council voted in favour of the US-backed plan for Gaza that authorises the international stabilisation force to assume broad security control of the Gaza Strip as Israeli forces withdraw from key areas.
Countries such as Egypt, Qatar, Jordan, Pakistan, Indonesia and Turkey expressed willingness to contribute troops to the 30,000-strong force once it received a UN mandate. However, several potential contributors have opposed using the force to make Hamas disarm.
Mr Trump told reporters on Monday that the stabilisation force was "already running" and that more countries would be added.
"I think that, in a form, it's already running. And it will get stronger and stronger," Mr Trump said in the Oval Office. "More and more countries are coming into it. They're already in, but they'll send any number of troops that I ask them to send. They want to see peace."
The US President said "more than 59 countries" were seeking to be involved in the force.
"We have many countries that are not even in the Middle East, but are fairly close to the Middle East, that want to be involved. It's been pretty amazing," he said.
