Israeli President Shimon Peres has said it is possible for Israelis and Palestinians to overcome differences and scepticism over peacemaking.

He said it is time to restart serious negotiations and conclude a peace treaty that has long eluded the two sides in the conflict.

"We shouldn't lose the opportunity because it will be replaced by a great disappointment," he told reporters on the sidelines of the World Economic Forum meeting on the shores of the Dead Sea in Jordan.

"For my experience, I believe it's possible to overcome it. It doesn't require too much time," he said.

US Secretary of State John Kerry, who is expected in Jordan later in the day, said Palestinians and Israelis must make hard decisions to move toward direct negotiations.