Russia's foreign minister is hosting a U.N. Security Council meeting on fighting terrorism, reinforcing a theme dominating much of this week's gathering of world leaders at the United Nations.

Conflicts in Syria, Iraq and Africa have sparked a mass exodus of people to Europe. Migration will be the subject of a high-level session Wednesday on the sidelines of the General Assembly's annual ministerial meeting.

The Israeli-Palestinian conflict will also be on agenda, with the so-called Quartet of Mideast mediators — the United Nations, the United States, the European Union and Russia — meeting alone first and then with key Mideast nations to discuss reviving long-stalled peace negotiations.

The Palestinians also plan a ceremony where President Mahmoud Abbas will raise their flag at the U.N. for the first time.