The United Nations Security Council on Wednesday announced that former prime minister of Portugal Antonio Guterres is the unanimous choice to be next secretary-general of the international body, AP reported. Guterres had served as the UN's refugee chief till December 2015.

The announcement was made by Russian UN Ambassador Vitaly Churkin. All 15 members of the Security Council voted to choose the new UN secretary-general from among 10 candidates in six polls.

Guterres had led all five previous polls. In the sixth poll, however, diplomats said he had received 13 "encourage" votes, no "discourage" votes and two "no opinion" votes, according to the AP report. The five UNSC members with the power to veto decisions used different colored ballots in the sixth vote.

The Security Council will meet on Thursday, October 6, to formally approve Guterres as the UN secretary-general and then recommend his nomination to the 193-member General Assembly, which must give final approval.

Current UN Secretary-General Ban Ki-moon's term expires in December 2016. He took office on January 1, 2007, and was re-elected to the post, unopposed for a second term, on June 21, 2011.