UN Secretary-General Antonio Guterres has warned that there is "no alternative" to a two-state solution to the Israel-Palestinian conflict, after a White House official said peace did not necessarily have to entail Palestinian statehood.

"There is no alternative solution for the situation between the Palestinians and Israelis, other than the solution of establishing two states and we should do all that can be done to maintain this," Guterres said during a visit to Cairo, echoing statements by Palestinian officials on Wednesday.

On Tuesday, a senior White House official said that the administration of US President Donald Trump would no longer seek to dictate an eventual peace settlement by insisting on a Palestinian state alongside Israel.

"Whether that comes in the form of a two-state solution if that's what the parties want, or something else," the official said at a press briefing, adding that Trump, while giving peace "high priority" would not try to "dictate" an agreement.

A two-state solution - the idea of Israel and Palestine living side-by-side and at peace - has been the bedrock of US diplomacy for the past two decades.

Palestinian officials also issued their warnings to the US against abandoning a two-state solution.

"If the Trump Administration rejects this policy it would be destroying the chances for peace and undermining American interests, standing and credibility abroad," Hanan Ashrawi, a senior member of the Palestine Liberation Organisation, said in response to the US official's remarks.

"Accommodating the most extreme and irresponsible elements in Israel and in the White House is no way to make responsible foreign policy," she said in a statement.

PLO Secretary-General Saeb Erekat said the organisation remained committed to two states and would oppose any system that discriminated against Palestinians. 

"Israel refuses one democratic secular state where Jews, Muslims and Christians can be equal, and those in government in Israel want to destroy the two-state solution," he told a press conference.

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Trump and the Israeli Prime Minister Benjamin Netanyahu are due to meet in Washington later on Wednesday for the first time since the US election in November that brought the Republican to office.

Al Jazeera's Bernard Smith, reporting from West Jerusalem, told Al Jazeera that Netanyahu's right-wing coalition partners were hoping that he would announce that he was abandoning a two-state solution during his visit to Washington.

"Netanyahu was asked on his way to Washington if he still supported the idea of two-state solution and he did not make any comments," Smith said.

"However, he told his cabinet meeting on Sunday in Jerusalem that he was not going to raise the issue of annexing parts of the West Bank or [the] idea of abandoning a two-state solution."

'State-minus'

While Netanyahu has said he is committed to a two-state goal, he has broadly reiterated the aim since bringing it up since 2009.

The right-wing Israeli leader has spoken of a "state minus", suggesting that he could offer the Palestinians deep-seated autonomy and the trappings of statehood without full sovereignty.

The Palestinians want an independent state in the West Bank and Gaza, with the capital in East Jerusalem, which Israel seized in the 1967 Middle East war.

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In their meeting, Trump and Netanyahu are expected to discuss peace efforts between Israel and Palestine, as well as expanding settlements, the Iran nuclear deal and the war in Syria.

Trump's campaign pledge to move the US embassy in Israel from Tel Aviv to Jerusalem, a move that would infuriate Palestinians and the Muslim world, will also be a discussion point.

US presidents have long maintained a close friendship with Israel, lavishing the country with aid and advanced weaponry.

But Trump's predecessor, Barack Obama, also highlighted Israeli actions seen as undermining peace efforts, such as expanding settlements in the occupied West Bank.

Source: Al Jazeera and news agencies