Portugal's former Prime Minister Antonio Guterres is poised to become the next UN secretary general, UN diplomats say.

Mr Guterres, 67, was the "clear favourite", Russia's UN ambassador Vitaly Churkin announced on Wednesday.

A formal vote will take place in the UN Security Council on Thursday to confirm the choice of nominee.

Mr Guterres, who led the UN refugee agency for 10 years, will take over from Ban Ki-moon early next year.

(CNN)