"The work that Saudi Arabia, the United States have been doing together in terms of our own agreements, I think, is potentially very close to completion," Blinken said in Riyadh at the World Economic Forum.

Blinken added that the implementation of a two-state solution for Palestine and Israel and the normalisation of relationships in the region with Israel would serve as the greatest rebuke to Iran and Hamas.

"I think the single biggest most effective rebuke to both Iran and Hamas would be Israel having normal relations with every country in this region, and the realisation of a Palestinian state", he said.

Blinken also said that he was hopeful Hamas would accept an "extraordinarily generous" offer to halt Israel's Gaza offensive in return for the release of captives.

"Hamas has before it a proposal that is extraordinarily, extraordinarily generous on the part of Israel," Blinken said.

"In this moment, the only thing standing between the people of Gaza and a ceasefire is Hamas," he said.

"They have to decide -- and they have to decide quickly," Blinken said. "I'm hopeful that they will make the right decision."

"We can have a fundamental change in the dynamic" in more than half a year of bloodshed, Blinken said.

A delegation from Hamas was due on Monday in Egypt, which with Qatar has been seeking to broker a deal that would halt the Israeli offensive and see captives freed.