The Trump administration's $US50 billion Middle East economic plan calls for the creation of a global investment fund to lift the Palestinian and neighbouring Arab state economies.

Senior PLO official Hanan Ashrawi said Kushner's plans were "all abstract promises" and only a political solution would solve the conflict.

Hamas, the Islamist militant group that controls Gaza, was more blunt, saying: "Palestine isn't for sale".

One proposal is for the construction of a $5 billion transportation corridor to connect the West Bank and Gaza.

The "peace to prosperity" plan is set to be presented at an international conference in Bahrain next week by Mr.Kushner, who told Reuters that Palestinian leaders should consider the initiative.

"This is going to be the 'Opportunity of the Century' if they have the courage to pursue it," he said.

However Ms.Ashrawi told Reuters the Trump administration's stance was an "entirely wrong approach", adding: "They can end the occupation, which is the most basic requirement for prosperity. There can be no prosperity under occupation."

"If they really care about the Palestinian economy they should start by lifting the siege of Gaza, stopping Israel stealing our money and our resources and our land and opening up our territorial waters, our air space and our borders so we can freely export and import."

Israeli Energy Minister Yuval Steinitz said the plan looked promising.

"What's been published until now looks good and even very good. We are always in favour of developing the Palestinian economy, ending the humanitarian crisis in Gaza, ensuring economic prosperity in the Palestinian communities," he told Israeli Reshet TV.

"The entire world wants to help the Palestinians except for the Palestinians themselves."

Several Gulf Arab states, including Saudi Arabia, will participate in the June 25-26 U.S.-led gathering in Manama.

Australian Associated Press