Portugal’s former Prime Minister Antonio Guterres has been officially appointed as the next UN secretary general, the BBC reports.

Mr Guterres, 67, will become the world’s top diplomat on 1 January when Ban Ki-moon’s second five-year term ends.

The Portuguese, who led the UN refugee agency UNHCR for 10 years, was chosen from among 13 candidates last week.

He said he would fulfil his role with gratitude and humility.

Mr Guterres, who trained as an engineer, entered politics in 1976 in Portugal’s first democratic election after the “Carnation revolution” that ended five decades of dictatorship.

As head of the UNHCR refugee agency from 2005 to 2015, he led the agency through some of the world’s worst refugee crises, including those in Syria, Afghanistan, and Iraq.

During that time, he repeatedly appealed to Western states to do more to help refugees fleeing the conflicts.