According to Bloomberg, the former Portuguese prime minister is expected to officially inform the president of the UN General Assembly "soon", according to the diplomats, speaking on condition of anonymity because the decision has not yet been made public, Bloomberg said.

António Guterres, 71, took up the post of UN Secretary-General in January 2017 to serve a five-year term that ends later this year.

According to diplomats, Guterres, who managed to avoid the wrath of US President Donald Trump, refraining from criticising him in public, wanted to wait for the results of the United States presidential elections in November, which gave Democrat Joe Biden victory , before making a decision.

The Trump Administration has repeatedly clashed with the UN and its organisations, even renouncing the World Health Organisation (WHO) and angering members of the Security Council when it unilaterally withdrew and tried to end the multinational nuclear agreement signed in 2015 with Iran.

President-elect Joe Biden promised, however, to reverse the United States' approach, returning to WHO and the Iran deal and rejoining the Paris agreement on climate change. During his term, Guterres made the issue of climate change his priority, putting pressure on countries to increase commitments to reduce carbon emissions. The Biden administration has signalled led that climate will be a top priority and his choice for UN ambassador, Linda Thomas-Greenfield, is an experienced diplomat on four continents. The last UN secretaries-general have always served two terms, so diplomats hope that the so-called P5 (the permanent members of the Security Council) - Russia, USA, United Kingdom, China and France - will support his candidacy for reelection. Lusa contacted António Guterres' office at the UN, but so far has not obtained any further information.