The probable next U.N. secretary-general says he faces "huge challenges" and hopes to see unity and consensus during his expected term at the international body.

Antonio Guterres praised the U.N. Security Council for its swiftness and unity in approving him by acclamation in a formal vote Thursday.

Guterres said he hoped the consensus would turn out to be symbolic, bringing "swift decisions which the troubled world we live in demands."

Guterres, a former Portuguese prime minister, is almost certain to replace Ban Ki-moon as secretary-general.

He spoke without notes in Portuguese, English, French and Spanish in a statement at the Foreign Ministry in Lisbon. He did not take reporters' questions.