Turkish President Recep Tayyip Erdogan addresses a crowd in Istanbul, May 18, 2018. Photo: Reuters / Murad Sezer.

Turkish President Recep Tayyip Erdogan on Friday criticized Saudi Arabia and other Gulf Arab nations for not speaking out against the US Middle East plan which he said endorsed the Israeli annexation of Palestinian lands.

Erdogan, who has positioned himself as a global champion for Muslim causes, said Arab nations’ stance toward Palestinians was pitiable and countries that failed to speak out would be responsible for “grave results.”

On Tuesday, US President Donald Trump proposed creating a demilitarized Palestinian state with borders drawn to meet Israeli security needs, granting American recognition of Israeli settlements in the West Bank and of Jerusalem as Israel‘s indivisible capital.

Turkey dismissed the plan as an attempt to steal Palestinian lands and kill off prospects of establishing a Palestinian state alongside Israel.

Despite Palestinians’ rejection of the plan and their boycott of Trump, three Gulf Arab states — Oman, Bahrain and the United Arab Emirates — attended the White House gathering where Trump announced his plan.

“When we look at the stance of countries in the Muslim world toward this step and the announced text, I pity us. Saudi Arabia mostly, you are silent. When will you speak? The same goes for Oman, Bahrain, the Abu Dhabi leadership,” Erdogan said in comments to members of his ruling party in Ankara.

“They even go and applaud it there. Shame on you,” he added. “Some Arab countries supporting such a plan are betraying Jerusalem, their own peoples and most of all humanity.”

Despite their historic support for Palestinians, some Arab powers have appeared to prioritize close ties with the United States and a shared hostility toward Iran over traditional Arab alliances.

Saudi Arabia expressed appreciation for Trump’s efforts and support for direct peace negotiations under US auspices, although state media reported that King Salman had called Palestinian Authority President Mahmoud Abbas to convey Riyadh’s unwavering support.

Turkey’s ties with Saudi Arabia, Egypt and the United Arab Emirates have been tense over a host of issues, from the killing of Saudi journalist Jamal Khashoggi at the Saudi consulate in Istanbul to rival policies in Libya.

Erdogan said it was “inexplicable” for Palestinians to be pressured into accepting the plan, adding that he would talk later on Friday to Abbas and the leader of Hamas, Ismail Haniyeh.

Abbas will speak at the United Nations Security Council about the plan.