Economic leaders convened by the United States in Bahrain on Wednesday voiced optimism for major economic growth in the Palestinian territories, whose leaders boycotted the workshop as a bid to impose terms of peace.

Jared Kushner, President Donald Trump's son-in-law and adviser, is leading the "Peace to Prosperity" initiative in the Arab kingdom in what he billed Tuesday as the "Opportunity of the Century" for the Palestinians.

But Kushner, a staunch supporter of Israel, said that the Palestinians needed to accept the economic framework before any eventual progress on reaching a long-elusive comprehensive peace deal.

On the second day of the conference in a luxury hotel on the Gulf, prominent figures in the global economy discussed Kushner's plan which speaks of $50 billion of investment in infrastructure, tourism and education.

"So if there is an economic plan, if there is urgency, it's a question of making sure that the momentum is sustained," said Christine Lagarde, the managing director of the International Monetary Fund.

"For that, it will require all the goodwill in the world on the part of all parties -- private sector, public sector, international organisations and the parties on the ground and their neighbours," she said.

The IMF has warned of severe deterioration in the Palestinian economy.

Tax revenue is being held up in a dispute with Israel, which has blockaded the Gaza Strip for more than a decade because of the Islamist movement Hamas' leadership of the crowded and impoverished territory.

Citing examples of post-conflict countries, Lagarde said that private investors needed progress in several areas including strengthening the central bank, better managing public finance and mobilising domestic revenue.

"If anti-corruption is really one of the imperatives of the authorities -- as it was in Rwanda, for instance -- then things can really take off," she said.

- Rejection by Palestinian leaders -

Thousands of Palestinians have taken to the streets to denounce the Bahrain conference, with a general strike shuttering most stores and restaurants in the Gaza Strip.

The Palestinian Authority fears that the Trump administration is dangling money to impose its own political solutions after already taking a series of landmark steps in support of Israel, including recognising Jerusalem as the Jewish state's capital.

The Trump administration has been pushing "the normalisation and support of Israel's colonial enterprise towards sustaining the Israeli occupation of Palestine," said Saeb Erekat, secretary general of the Palestine Liberation Organisation.

Some Palestinian protesters burned pictures of Trump and the king of Bahrain, a steadfast US ally who like other Gulf Arabs has increasingly found common cause with Israel due to mutual hostility with Iran.

In unprecedented scenes, Israeli academics and journalists openly travelled to Bahrain, mingling with Gulf Arab officials over tables of freshly brewed coffee and chocolate biscuits.

- Private-sector push -

Saudi Minister of State Mohammed al-Shaikh, a key planner of the kingdom's economy, voiced hope that the private sector could help achieve the Kushner plan.

He noted that the Palestinians saw an influx of governmental money in the optimistic days after the 1993 Oslo Accords, which had provided some self-governance to the West Bank and Gaza.

"If we managed to do it 25 years ago with significantly less money, I'm pretty sure it can be done today with the amounts of money and the private sector's participation," he said.

Not all are as optimistic. Jordan and Egypt, the two Arab nations that have made peace with Israel, sent only mid-level delegations, with Jordan insisting that the Bahrain conference was not a substitute for a peace deal.

The Soufan Center research group doubted that the United States could be considered an honest broker after Trump's moves, which also include ending funding for the UN body for Palestinian refugees.

"To anyone paying close attention," it said in an analysis, the workshop "appears to be a waste of time."