The UN's Middle East coordinator, Nickolay Mladenov, was invited to the June 25-26 conference in Manama, but he will not attending.

"At this stage, I'm not aware that we will have anyone present," said UN spokesman Farhan Haq when asked about UN attendance at the conference.

President Donald Trump's son-in-law Jared Kushner has been drafting the long-awaited peace plan that has already been rejected by the Palestinians, who expect the proposals to heavily favor Israel.

The plan is aimed at providing economic opportunities for the Palestinians, but Kushner has hinted that it will not endorse international calls for the creation of a Palestinian state.

Several UN resolutions have enshrined the two-state solution to the Israeli-Palestinian conflict as the path to a peace settlement.

The Palestinian Authority has already said it will boycott the Bahrain conference after it cut ties with the US administration over Trump's recognition of Jerusalem as Israel's capital.

UN diplomats say they expect the Kushner plan to fail, but it remains unclear what other course of action could be taken to advance Israeli-Palestinian peace.