JERUSALEM - US President Donald Trump's adviser Jared Kushner on Sunday questioned the ability and willingness of Palestinian president Mahmud Abbas to make concessions for a peace agreement with Israel.

Kushner's remarks, made in a rare interview with Palestinian newspaper Al Quds, came as he and special envoy Jason Greenblatt were in the region to advance efforts to renew the stalled Israeli-Palestinian peace process.

The US duo have not met with Palestinian officials, who froze all contact with US officials following the Trump administration's December recognition of Jerusalem as Israel's capital.

"President Abbas says that he is committed to peace and I have no reason not to believe him," Kusnher said. "However, I do question how much President Abbas has the ability to, or is willing to, lean into

finishing a deal."

"He has his talking points which have not changed in the last 25 years. There has been no peace deal achieved in that time," Kushner said.

"To make a deal both sides will have to take a leap and meet somewhere between their stated positions. I am not sure President Abbas has the ability to do that."

Kushner and Greenblatt met on Friday with Israeli Prime Minister Benjamin Netanyahu to discuss "advancing the diplomatic process, developments in the region and the security and humanitarian situations in Gaza", according to the premier's office.

They held a second meeting Saturday night "to continue their discussions," the White House said.

The visit comes after a flare-up of hostilities between Israel and the Hamas-ruled Gaza Strip.

Israel pounded Hamas targets in response to a barrage of rockets and mortar shells, while troops have killed over 130 Palestinians taking part in clashes on the fringes of demonstrations.

Speaking at his Sunday cabinet meeting, Netanyahu said the US officials "fully supported our position and actions to ensure the security of Israel and its civilians around Gaza".

The Palestinians have been infuriated by Trump's policies and see east Jerusalem as their future capital, insisting the status of the disputed city is an issue to be negotiated between them and the Israelis.

Senior Palestinian official and chief negotiator Saeb Erekat said Sunday that Kushner's interview showed "there's nothing of substance" coming from the Trump Administration.

"Kushner represents a policy of dictation rather than negotiations. It is the Trump Administration that has walked away from the negotiations, from international law and UN resolutions," Erekat said.

Trump has called peace between Israel and the Palestinians the "ultimate deal" and has tasked Kushner with formulating a plan to that end.

Kushner - who has also visit Jordan, Egypt and Saudi Arabia on the trip - told Al Quds they were "almost done" preparing the plan, which could be presented without Palestinian consent

"If President Abbas is willing to come back to the table, we are ready to engage; if he is not, we will likely air the plan publicly," he said.