A White House official says that Egypt, Jordan and Morocco have confirmed their attendance at a U.S. conference this month in Bahrain, where the administration will unveil the economic portion of its plan for Mideast peace.

The White House hailed the attendance of the Arab states Tuesday as a sign "that our workshop is gathering momentum."

The level of the countries' representatives was not known, but the U.S. had extended invitations to finance ministers.

Presidential advisers Jared Kushner and Jason Greenblatt personally appealed to the kings of Morocco and Jordan during their recent trip to the region.

The U.S. hopes to draw Arab states with deep pockets to participate in the workshop, which envisions investment in the Palestinian territories. The Palestinians have rejected the plan, citing the Trump administration's pro-Israel bias.