RAMALLAH, WEST BANK (Reuters) - A powerful but rarely convened assembly that calls itself the Palestinian “supreme authority” met for the first time in 22 years on Monday, with boycotts and rifts suggesting it will struggle to achieve its stated goal of unity.

Palestinian President Mahmoud Abbas gestures during the Palestinian National Council meeting in Ramallah, in the occupied West Bank April 30, 2018. Palestinian President Office (PPO)/Handout via REUTERS

In a two-hour opening address to the Palestinian National Council (PNC) President Mahmoud Abbas criticized U.S. President Donald Trump’s decisions last year to recognize Jerusalem as Israel’s capital, and to move the U.S. Embassy to the city.

Abbas told the de facto parliament of the Palestine Liberation Organisation that the American stance favoring Israel might require “tough decisions in the near future.”

“If America wants to offer something let them say they support the two-state solution with east Jerusalem as the capital of Palestine and that it (U.S.) is no longer a sole mediator,” he said.

U.S. Secretary of State Mike Pompeo suggested on Monday he was open to a two-state solution to the Israeli-Palestinian dispute, saying a “two-party solution” was likely in his first extensive comments on peace efforts since taking the job last week.

“With respect to the two-state solution, the parties will ultimately make the decision. We are certainly open to a two-party solution as a likely outcome,” Pompeo said at a news conference in Jordan after a visit to Israel.

Abbas is expected to use the four-day meeting of the PNC to renew his legitimacy and to install loyalists in powerful positions to begin shaping his legacy.

The 82-year-old leader told the 600 PNC members present that the council - powerful but little-known outside Palestinian political circles - was “very important because it protects the Palestinian dream.”

However his handling of the meeting has met with widespread criticism - about the location of the session, its timing and who is and is not attending.

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Islamist groups have boycotted it, and earlier on Monday Hamas leader Ismail Haniyeh dismissed the session as a “clapping party” for Abbas.

“Is it logical that the PLO be the sole representative of the Palestinian people when it does not include Hamas and Islamic Jihad?” asked Haniyeh.

Hamas defeated Abbas’s western-backed Fatah in parliamentary elections in 2006 and has been locked in rivalry with it since. Attempts at reconciliation have faltered over power-sharing disputes.

In his speech Abbas restated his demand that Hamas relinquish full control of Gaza to his western-based Palestinian Authority, whose power base is in the West Bank.

But not all the criticism came from outsiders. Three factions within the umbrella PLO said they would boycott the 700-member assembly, including the Popular Front for the Liberation of Palestine, the second largest group.

It wanted the meeting to be postponed to allow more time for reconciliation efforts between Fatah and Hamas, and to ensure broader participation.

“COLLECTIVE YAWN”

Mahdi Abdul-Hadi, a Jerusalem-based analyst, said Abbas seemed intent on driving through his own agenda and replacing enemies with loyalists on the PLO’s powerful Executive Committee, whose members are appointed by the PNC.

“He needs to re-inject legitimacy and the recognition of his authority,” said Abdul-Hadi.

On its website the PNC says it “represents the supreme authority of the Palestinian people in all their places of residence.”

But its aging leadership - Abbas will be 83 later this year and PNC chairman Saleem Al-Zanoon is 85 - has many younger Palestinians questioning its relevance, especially those who can barely remember its last full meeting in 1996.

“This PNC will not deliver me or my generation; it won’t deliver the diaspora or Gaza. The PNC is not delivering an entire generation that views these meetings with a collective yawn,” said Diana Buttu, a Canadian-born former legal adviser to Palestinian peace negotiators, who now lives in Haifa.

“Abbas may think that this will grant him ‘legitimacy’ but the question remains - legitimacy from whom?”

U.N. Middle East envoy Nickolay Mladenov welcomed the meeting, but urged Abbas to work for unity. “The leadership has a responsibility to end divisions and the deteriorating economic, humanitarian and social situation in Gaza,” he said in a statement.