Arab leaders have demanded a two-state solution to the decades-long Israeli-Palestinian conflict amid increased unease over the stance of the United States under the administration of President Donald Trump.

The heads of Arab League states - attending a one-day summit beside the Dead Sea in Jordan - did not publicly refer to Trump or his statements on Wednesday, but they stressed their own continued backing for an independent Palestinian state.

Sheikh Tamim bin Hamad Al Thani, Qatar's Emir, said: "We are required to jointly and seriously act to put pressure on the international community and the [UN] Security Council to reject the inception of an apartheid system in the 21st century."

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He added it was necessary "to deal firmly with Israel to force it to stop building settlements, implement international legitimacy resolutions, end the continuous violations against the Palestinian people, and lift the unjust siege imposed on the Gaza Strip".

The summit's host, King Abdullah of Jordan, said the creation of a Palestinian state alongside Israel remained the basis of any comprehensive peace deal.

"Israel is continuing to expand settlements and wreck chances of peace... There is no peace or stability in the region without a just and comprehensive solution to the Palestinian cause through a two-state solution," he said.

Palestinian President Mahmoud Abbas also criticised Israeli policy in his speech.

"The Israeli government has since 2009 worked on wrecking the two-state solution by accelerating the tempo of settlements and the confiscation of land," Abbas told the Arab leaders.

UN Secretary-General Antonio Guterres reiterated the calls, telling summit participants via video conference that two states are the "only path to ensure that Palestinians and Israelis can realise their national aspirations and live in peace, security and dignity".

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Trump rattled Arab and European leaders in February by indicating he was open to a one-state solution, upending a position taken by successive US administrations and the international community.

Trump later told Reuters news agency in an interview he liked the concept of a two-state solution, but he stopped short of reasserting a US commitment to eventual Palestinian statehood, saying he would be "satisfied with whatever makes both parties happy".

This week Israeli Prime Minister Benjamin Netanyahu said he was committed to work with Trump to advance peace efforts with the Palestinians, but he also stopped short of reiterating a commitment to a two-state solution.

Trump's Middle East envoy Jason Greenblatt met Abbas ahead of Wednesday's summit, the second such meeting in two weeks. Trump has also invited Abbas to the White House.

"[Greenblatt] had a lot of queries and we are answering them to complete the picture in their minds and speaking as Arabs in one language," Abbas said, adding he had told the envoy that Palestinians remained as firm as ever in their demand for an independent state.

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The Palestinians and other Arabs want East Jerusalem - which Israel captured in a 1967 war and later annexed in a move not recognised internationally - as the capital of a future state encompassing the Israeli-occupied West Bank and the Gaza Strip.

King Abdullah, whose dynasty has custodianship over Muslim holy sites in Jerusalem, said any unilateral Israeli move to change the status quo in the Dome of the Rock and al-Aqsa Mosque would have "catastrophic" consequences for the future of the region.