In Israel, Tzachi Hanegbi, a cabinet member close to Prime Minister Benjamin Netanyahu, described Palestinians' rejection of the "peace to prosperity" plan as tragic.

Set to be presented by Trump's son-in-law Jared Kushner at a conference in Bahrain on June 25-26, the blueprint envisions a global investment fund to lift the Palestinian and neighbouring Arab economies and is part of broader efforts to revive the Israeli-Palestininan peace process.

"We don't need the Bahrain meeting to build our country, we need peace, and the sequence of (the plan) -- economic revival followed by peace is unrealistic and an illusion," Palestinian Finance Minister Shukri Bishara said on Sunday.

The lack of a political solution, which Washington has said would be unveiled later, prompted rejection not only from Palestinians but also in Arab countries.

From Sudan to Kuwait, commentators and ordinary citizens denounced Kushner's proposals in strikingly similar terms: "colossal waste of time", "non-starter", "dead on arrival".

Egyptian liberal and leftist parties slammed the workshop as an attempt to "consecrate and legitimise" occupation of Arab land and said in a joint statement that any Arab participation would be "beyond the limits of normalisation" with Israel.

The precise outline of the political plan has been shrouded in secrecy, but officials briefed on it say Kushner has jettisoned the two-state solution - the long-standing worldwide formula that envisages an independent Palestinian state alongside Israel in the West Bank, East Jerusalem and Gaza.

The Palestinian Authority is boycotting the Bahrain meeting, saying only a political solution will solve the problem. It said Kushner's "abstract promises" were an attempt to bribe Palestinians into accepting Israeli occupation.

The White House has not invited the Israeli government to Bahrain.

US-allied Gulf states, including Saudi Arabia and the United Arab Emirates, will take part in the Bahrain gathering along with officials from Egypt, Jordan and Morocco. Lebanon and Iraq will not attend.

"Those who think that waving billions of dollars can lure Lebanon, which is under the weight of a suffocating economic crisis, into succumbing or bartering over its principles are mistaken," parliament Speaker Nabih Berri said.

Thousands of people marched through the Moroccan capital Rabat on Sunday to express their solidarity with the Palestinians and their opposition to the Kushner plan.

"We came here to speak in one voice as Moroccans and express our rejection of all conspiracies that target the Palestinian cause," Slimane Amrani, vice secretary general of the kingdom's co-ruling Islamist PJD party told Reuters.

Arab analysts believe Kushner's economic plan is an attempt to buy off opposition to Israel's occupation of Palestinian land with a multibillion-dollar bribe to pay off the neighbouring hosts of millions of Palestinian refugees to integrate them.

In recent years, Iran's bitter rivalry with a bloc led by Sunni Muslim Saudi Arabia has increasingly pushed the Arab-Israeli struggle into the background.

While Riyadh and its allies have welcomed Trump's harder line against Tehran, which has cast itself as the guardian of Palestinian rights, critics accuse Saudi Arabia, the custodian of Islam's holiest places, of abandoning the Palestinians.

Riyadh has assured Arab allies it would not endorse anything that fails to meet key Palestinian demands.

Ali Shihabi, who heads the Arabia Foundation which supports Saudi policies, said the Palestinian Authority was wrong to reject the plan out of hand.

Yet even in the Gulf, backing for Kushner's plan is limited.

"The deal of the century is a... one-sided concession, the Arab side, while the occupier wins everything: land, peace and Gulf money," said Kuwaiti parliamentarian Osama Al-Shaheen.

Australian Associated Press