Palestine Liberation Organisation number two Saeb Erekat says the result of US decisions on Jerusalem would be "blatant provocation to all Arabs and Muslims."
The Palestinian leadership on Friday slammed a US decision to open its embassy in Jerusalem in May, coinciding with the 70th anniversary of Israel's independence, as "a provocation to Arabs".
US President Donald Trump announced last December that the United States recognised Jerusalem as Israel's capital, infuriating even Washington's Arab allies and dismaying Palestinians who want the eastern part of the city as their capital.
"We are excited about taking this historic step and look forward with anticipation to the May opening," US State Department spokeswoman Heather Nauert said, noting that it will coincide with Israel's 70th anniversary.
The founding of Israel seven decades ago on May 14, 1948 is mourned by Palestinians as the Nakba, or "catastrophe."
"The American administration's decisions to recognise Jerusalem as Israel's capital and choose the Palestinian people's Nakba as the date for this step is a blatant violation of international law," Palestine Liberation Organisation (PLO) number two Saeb Erekat told AFP.
He said the result would be "the destruction of the two state option, as well as a blatant provocation to all Arabs and Muslims."
"This is an unacceptable step. Any unilateral move will not give legitimacy to anyone and will be an obstacle to any effort to create peace in the region," said Nabil Abu Rdainah, a spokesman for the Palestinian president, Mahmoud Abbas, who is in the United States until Saturday.
Israel follows the Jewish lunar calendar and this year's official independence celebration falls on April 19.
TRT World spoke to journalist Giles Gibson.
The embassy in Jerusalem will be gradually expanded in existing consular facilities in the Arnona neighbourhood, while the search for a permanent site has already begun for what Nauert called a "longer-term undertaking."
The interim embassy will have office space for the ambassador and a small staff and, by the end of 2019, a new embassy annex on the Arnona compound will be opened, Nauert said in a statement.
The consulate in East Jerusalem will continue to serve Palestinians, and for security reasons US Ambassador David Friedman will continue living in the residence in Herzliya, north of Tel Aviv, and commute to the relocated embassy, another official said, speaking on the condition of anonymity.
A May opening is earlier than expected – US Vice President Mike Pence told the Israeli parliament last month that the move would take place by the end of 2019.
Israel welcomes US decision
Israeli intelligence minister Israel Katz was quick to welcome the opening date.
I would like to congratulate Donald Trump, the President of the US @POTUS on his decision to transfer the US Embassy to our capital on Israel's 70th Independence Day. There is no greater gift than that! The most just and correct move. Thanks friend!— ישראל כץ Israel Katz (@Israel_katz) February 23, 2018
"I would like to congratulate Donald Trump, the President of the US on his decision to transfer the US Embassy to our capital on Israel's 70th Independence Day," he wrote in English on his Twitter account.
"There is no greater gift than that! The most just and correct move. Thanks friend!"
US President Donald Trump in December broke with decades of policy in Washington by officially recognising Jerusalem as Israel's capital and pledging to move the American embassy from Tel Aviv.
No other country has recognised Jerusalem as Israel's capital and Trump's decision has sown discord between the United States and the EU over Middle East peace efforts.