Donald Trump’s Middle East peace envoy is leaving the White House before the full publication of the administration’s Middle East peace plan, raising further doubts about its viability.

In tweets on Thursday, by Mr Trump revealed that Jason Greenblatt, his special representative for international negotiations, would be leaving after almost three years in the role “to pursue work in the private sector.”

He praised Mr Greenblatt, who had previously worked as executive vice president and chief legal officer to the Trump organisation, as “a loyal and great friend”, stating that his “dedication to Israel and to seeking peace between Israel and the Palestinians won’t be forgotten.”

For the last few years, Mr Greenblatt has been working together with Jared Kushner, Mr Trump’s son-in-law, on a peace plan between Israel and the Palestinians, which Mr Trump has touted as the “deal of the century”. The first part of the plan, focusing on an economic future for the region, was released in June, to considerable scepticism.

The second part, providing a political road map, is expected to be far more controversial. Its release has been repeatedly delayed, with US administration officials most recently confirming that it would not be published until after the Israeli elections later this month.

One official told the New York Times that “the vision is now complete and will be released when appropriate.”

In a statement, Mr Greenblatt, who is Jewish, described having worked in the White House as “the honour of a lifetime” and said he was “grateful to have been part of the team that drafted a realistic vision for peace, which has the potential to improve the lives of millions of Israelis, Palestinians and others in the region.”

Jared Kushner praised what he described as Mr Greenblatt’s “tremendous job leading the efforts to develop an economic and political vision for a long sought after peace in the Middle East.

“His work has helped develop the relationships between Israel and its neighbours as he is trusted and respected by all of the leaders throughout the region."

During his time as a Middle East envoy, Mr Greenblatt was criticised for his supposedly partisan nature, particularly his willingness to criticise the actions of Palestinian officials while keeping silent on actions from the Israeli government viewed as being unconducive to peace.

In June, when asked by CNN whether he had ever criticised the Israeli government or Israeli Prime Minister Benjamin Netanyahu, he responded by saying, "I haven't found anything to criticise that goes over the line."

It is understood that Avi Berkowitz, an advisor to Mr Kushner who has also worked on the Trump Peace Plan, will take over many of Mr Greenblatt’s duties.