U.S. Special Representative for International Negotiations Jason Greenblatt lambasted the Palestinian Authority on Sunday after an opinion piece in its official outlet, the daily Al-Hayat al-Jadida, compared  him to a mongoloid.

The opinion piece was written by Omar Hilmi Al-Ghoul, who used to be an adviser to former P.A. Prime Minister Salam Fayyad. The piece was laden with derogatory descriptions of Greenblatt and other senior officials in the White House who are part of its Mideast peace team.

“The comments of Omar Hilmi Al-Ghoul are disgusting & demonstrate a complete disregard for the dignity of every human life,” Greenblatt attacked on twitter shortly after the piece was published. “Terms like mongoloid & retarded, have no place in a civilized world. Persons with Down syndrome deserve our utmost respect & love. Shame on you Omar!”

According to a translation on the site Palestinian Media Watch, Al-Ghoul wrote: “Anyone who follows the prattle of Jason Greenblatt, President Trump’s envoy in the matter of the deal of the century, sees that his condition is very similar to Down Syndrome. … Anyone who looks at the American envoy [Greenblatt] discovers that he has external and inner characteristics similar to those suffering from Down Syndrome: He is short, his eyes are similar to mongoloid eyes, he prattles unrestrainedly, and is politically retarded.””

Al-Ghoul also attacked White House senior adviser and presidential son-in-law Jared Kushner and U.S. Ambassador to Israel David Friedman, who are both, along with Greenblatt, part of the team working on the Mideast peace plan, set to be unveiled after the April 9 national elections in Israel.