Updated

The Security Council unanimously agreed Wednesday that Portugal's former prime minister Antonio Guterres should be the next secretary-general of the United Nations.

Russia's U.N. Ambassador Vitaly Churkin made the announcement to reporters surrounded by the 14 other council ambassadors after they held a sixth informal poll of the 10 candidates behind closed doors.

Churkin announced that the council would hold a formal vote on Thursday morning to recommend Guterres to the 193-member General Assembly, which must approve a successor to Ban Ki-moon whose second five-year term ends on Dec. 31.

By tradition, the job of secretary-general has rotated among regions. Asia, Africa, Latin America and Europe have all held the post. East European nations, including Russia, argue that they have never had a secretary-general and it was their turn. There has also never been a woman secretary-general and more than 50 nations and many others campaigned to elect the first female U.N. chief.

But Guterres, who served as the U.N.'s high commissioner for refugees until December, topped all six polls despite being a man from Western Europe.

For the first time this year, the General Assembly's members held two-hour question-and-answer sessions with all 13 candidates who entered the race, and in the eyes of many diplomats Guterres performed best.

In the fifth "straw" poll, however, he still received two "discourage" votes and there was a lot of speculation about whether Russia, which is a member of the East European group, would vote for him.

The sixth informal poll on Wednesday morning was the first to use colored ballots to distinguish the votes of the five veto-wielding Security Council members -- the United States, Russia, China, Britain and France. Diplomats said in the vote that Guterres received 13 "encourage" votes, no "discourage" votes, and two "no opinion."

Churkin paid tribute to all 13 candidates who entered the race before announcing the Security Council's support for Guterres. Three dropped out before Wednesday's vote, leaving five men and five women in the race.