Washington DC - President Donald Trump said Monday he was not confident a ceasefire deal in Gaza would hold, despite trumpeting his diplomacy to secure it ahead of his inauguration.

Asked by a reporter as he returned to the White House whether the two sides would maintain the truce and move on in the agreement, Trump said, "I'm not confident."

"That's not our war; it's their war. But I'm not confident," Trump said.

Trump said that he believed Hamas had been "weakened" in the 15-month genocide that began October 7, 2023.

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"I looked at a picture of Gaza. Gaza is like a massive demolition site," Trump said.

The property tycoon turned politician said that Gaza could see a "fantastic" reconstruction if the plan moves ahead.

"It's a phenomenal location on the sea – best weather. You know, everything's good. It's like, some beautiful things could be done with it," he said.

Israel and Hamas on Sunday began implementing a ceasefire deal that included the exchange of hostages and prisoners.

The plan was originally outlined by then president Joe Biden in May and was pushed through after joint diplomacy by Biden and Trump envoys.

Trump, while pushing for the deal, has also made clear he will steadfastly support Israel.

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In one of his first acts, he revoked sanctions on extremist Israeli settlers in the West Bank imposed by the Biden administration over attacks against Palestinians.

Trump's airing of doubt marks a shift in tone from Biden, who had attempted for months to put the deal together.

"I'm confident," Biden told reporters on Sunday about the prospects for the accord after implementation began.

Trump in his inaugural address on Monday pointed to the ceasefire as he described himself as a "peacemaker." At a rally afterward in an indoor stadium, Trump invited family members of hostages still in Gaza.