The United States is seeking to "maximize Zionist interests" and neglecting legitimate Palestinian demands, said Iranian President Hassan Rouhani on Wednesday.
"Islamic countries should unanimously emphasize their principled position in opposing the recent U.S. move in talks with partners of the U.S., especially European countries," Rouhani said during his speech at an extraordinary summit of the Organization of Islamic Cooperation (OIC) in Istanbul.
The OIC is the second-largest inter-governmental body after the United Nations, and its 57 member states spread over four continents.
Rohani accused the U.S. of never been an honest mediator in the peace process and called on the Islamic world to unite against the "Zionist regime".
"Iran is ready to cooperate without preconditions with all Islamic countries to defend Jerusalem.
"The Zionist movements should be continuously monitored and the OIC should meet if necessary to take the measures at the level of ministers or heads of the states," the president noted.
Last week, Trump announced his decision -- despite widespread opposition -- to formally recognize Jerusalem as Israel's capital and relocate Washington's embassy from Tel Aviv to the holy city.
The announcement sparked strong condemnation from around the world, including Turkey, the EU and the UN.
Jerusalem remains at the core of the Israel-Palestine conflict, with Palestinians hoping that East Jerusalem -- now occupied by Israel -- might eventually serve as the capital of a future Palestinian state.
The OIC was established during a historic summit in Rabat, Morocco in 1969 following an arson attack on the Al-Aqsa Mosque in occupied Jerusalem.
Al-Aqsa was set on fire by an Australian Christian called Michael Denis Rohan on Aug. 21, 1969. The shrine and a 1,000-year-old pulpit were totally destroyed as well as several historical sites.
Rohan had joined a U.S.-based sect called "The Church of God" and believed that setting fire to Al-Aqsa would hasten the coming of the Messiah.
He was later declared mentally unstable and is reported to have died in psychiatric care in 1995.
