Senior White House adviser and President Donald Trump's son-in-law Jared Kushner is leading a U.S. delegation on stops in Morocco, Jordan and Israel this week seeking support for as-yet unveiled Israeli-Palestinian peace plan and a late June workshop aimed at helping the Palestinians.

Kushner is accompanied by Jason Greenblatt, Trump's special representative to Israel-Palestine negotiations, Brian Hook, the special US representative for Iran and his aide Avi Berkowitz, according to White House officials speaking to agencies in condition of anonymity. The delegation began their trip in Rabat and were to travel to Amman and Jerusalem, arriving in Israel on Thursday.

Kushner will then meet up with Trump in London when the president makes a state visit there next week.

The trip is similar to one that Kushner and Greenblatt took in February to Gulf states to drum up support for the economic portion of a Middle East peace plan that they have been developing on behalf of Trump.

The official said one reason for this week's trip is to bolster support for a June 25-26 conference in Manama, Bahrain, in which Kushner is to unveil the first part of Trump's long-awaited Israeli-Palestinian peace plan.

The plan, touted by Trump as the "deal of the century," is to encourage investment in the West Bank and Gaza Strip by Arab donor countries before grappling with thorny political issues at the heart of the conflict.

Palestinian leaders have been sharply critical of the effort and have urged Arab nations to avoid the conference. Saudi Arabia and the United Arab Emirates have said they will participate, and a senior U.S. official said officials from Qatar have said privately their country was expected to attend as well.

The participants in the conference in Manama are expected to include 300 to 400 representatives and business executives from Europe, the Middle East and Asia, and possibly some Palestinian business leaders.

A source familiar with the planning said it appeared Egypt, Jordan and Oman, as well as the G7 countries, would be sending representatives to the conference.