The UN Security Council will hold an emergency meeting on Egypt at 2130 GMT on Thursday, following a request from France, Britain and Australia, diplomats said.
The meeting comes a day after a crackdown by Egyptian security forces on protesters backing the deposed Islamist president Mohamed Morsi, which left more than 500 people dead.
France and Britain are permanent members of the Security Council and Australia is one of the 15 countries currently represented.
One diplomat said the joint request had been submitted to Argentina, which currently presides over the council. The diplomat added that a Council statement was not likely.
United Nations Secretary General Ban Ki-moon has condemned the crackdown, and UN rights chief Navi Pillay demanded that a wide-ranging probe be carried out.
Earlier Thursday, Turkish Prime Minister Recep Tayyip Erdogan called for an urgent Security Council meeting.
"This is a very serious massacre... against the Egyptian people who were only protesting peacefully," Erdogan said, criticizing "the silence" of the global community in the face of the bloodshed.