Saudi Arabia's defence minister delivered a blunt message to Iranian officials in Tehran last month: take President Donald Trump's offer to negotiate a nuclear agreement seriously because it presents a way to avoid the risk of war with Israel.

The 13-point US plan outlines a 60-day truce, mutual hostage and prisoner releases, and structured talks on Gaza's future, along with the Hamas' release of 10 living Israeli captives and the remains of 18 others in two stages, according to Israeli and American media and Palestinian sources.

Any Israeli campaign on Iran without the U.S. support will face severe limitations given the long distance between the two countries.