Zahir al-Harithi, head of the External Relations Committee of the Consultative Assembly of Saudi Arabia, slammed Trump's decision on Jerusalem as "catastrophic."
"I do not know any other decision by the White House that would have caused such a storm of discontent, indignation and contempt, like this move of President Trump," al-Harithi said.
Touching upon the reactions observed throughout the Arab world, he warned of "the unprecedented consequences" of Trump's decision.
READ MORE: Hamas Leader Calls for New Intifada, Bibi Urges World to Follow Trump's Example
According to al-Harithi, it will complicate the process of reaching a political peace settlement and pave the way for a new round of extremism and hatred in the region.
"Trump has ignored all the warnings and showed his biased stance on the matter. By making such a decision, he signaled his inability to comprehend a spate of historical and political nuances pertaining to the issue," al-Harithi pointed out.
He added that Trump surprised everyone with his "extremely dangerous decision" and dealt a blow to international agreements related to the peaceful settlement of the situation around the Palestinian Authority.
Al-Harithi warned that all this may be followed by a reaction that has never been taken into account before. He urged the international community "to send a political appeal to Washington to force it to review this catastrophic decision."
He was echoed by Muhammed Qabbani, a member of the Lebanese parliament, who described Trump's decision as "an enemy position in relation to Palestinians and Arabs as well as all Muslims and Christians.
If Palestinians respond to Trump's announcement with anger in the streets we will be told: see, who can make peace with those violent Arabs.
— (((YousefMunayyer))) (@YousefMunayyer) 7 декабря 2017 г.
If they don't we will be told: See, the Jerusalem decision was the right move.
Both of these are wrong.
Qabbani recalled that Jerusalem is known to be the most sacred city for Christians, while for Muslims its significance as a holy city is only less than that of Mecca and Medina.
"From now on, the US will be unable to take part in the political settlement of the Palestinian issue. They have sided with both Israel and extremists. The reaction to this will come from all across the world," he said.
The capital, the soul of #Palestine is #Jerusalem. Now from there the Palestinians protest against Trump's decision #JerusalemIsTheCapitalofPalestine #HandsOffJerusalem #FreePalestine pic.twitter.com/Nli7ymf96s
— Pal_st (@Stefaniafodd) 7 декабря 2017 г.
Qabbani called for the Arab League to convene a summit and for the meeting of the Organization of Islamic Cooperation in Istanbul in order to hammer out a response that would reduce the negative impact of Trump's decision on the Palestinians and the city's shrines.
READ MORE: Ambassador: 'Trump's Decision on Jerusalem Will Affect Entire World'
Earlier on Thursday, Hamas leader Ismail Haniyeh pledged to launch "an intifada in the face of the Zionist enemy," urging Arab countries to halt all cooperation with the United States.
He also claimed that President Trump will come to regret his decision on Jerusalem.