The Western-backed Syrian National Coalition opposition group said its leader met with U.N. Secretary-General Ban Ki-moon and urged him to speak out against Russian airstrikes, as a U.N. gathering of world leaders neared its end Saturday.

A coalition statement says Khaled Khoja met with Ban on Friday as the world hurried to react to Russia's dramatic new military moves in Syria this week.

The U.N. chief's stance "must be stronger and must condemn the over 50 innocent civilian casualties of the Russian airstrikes," the statement says.

The U.N. did not publish a meeting summary, as it does for Ban's meetings. On Saturday morning, a spokesman for Ban said one would not be issued.

Russia has dismissed accusations that its airstrikes have killed civilians and said it is targeting only the Islamic State and similar groups, not the opposition. Syrian and Russian military officials said Saturday that a new wave of Russian airstrikes attacked the Islamic State group and other insurgents in central and northern Syria.

The Syrian National Coalition statement says Friday's discussion with the U.N. secretary-general was "constructive and frank," and Khoja warned Ban that Syrians "were losing faith in the U.N., and needed the U.N. to stand beside them."

The U.N. chief has spoken repeatedly of his "shame" that Syria's grinding conflict has not been resolved, and his frustration with the deep divide in the Security Council, the U.N.'s most powerful body, on Syria is clear with veto-wielding permanent members on opposite sides. Russia and China support the government of Syrian President Bashar Assad, while the United States, Britain and France demand his ouster in a transition process.

Ban kicked off the annual U.N. General Assembly of world leaders on Monday by calling for the first time for Syria's situation to be referred to the International Criminal Court. But because that requires approval by the council, where Russia and China have vetoed several proposals on Syria during the civil war, Ban's call likely will go nowhere.

Also Saturday, the final speakers to the General Assembly included Hungary, which continued its strong stance against the flood of refugees and migrants into Europe, and Oman, which warned that the violence in Yemen is giving several extremist groups a base of operations.