US President Donald Trump's son-in-law and Gaza envoy Jared Kushner said on Monday that he had a "very cordial" meeting with Hamas and that getting the group to disarm and move forward with Trump's peace plan could materialise in about a month.

“Our meeting with Hamas was very cordial, and they said all the right things, so we’re going to give them a chance to prove it,” Kushner said, adding that “it will depend on Hamas’ actions and practical steps and I hope they are sincere in that”.

"We could be seeing progress... in as little as 30 days, hopefully starting to take some of the weapons out, and hopefully, you know, filling in some of the tunnels as well," Kushner told Fox News while in Tel Aviv.

"If Hamas voluntarily surrenders its weapons and tunnels within the next 60 to 90 days, it will mean the removal of a major security threat, an almost unimaginable achievement," he said.

However, he added that Trump's "Board of Peace" will "not restrict Israel’s right to defend itself if there are any imminent threats".

Kushner said if Hamas doesn’t fulfil its commitments now, "everyone will see that it’s not serious about peace, and then Israel will have much greater support from the United States and other countries to move forward and finish the job properly".