Portugal's government has proposed Antonio Guterres, a former UN high commissioner for refugees, as a candidate for secretary-general of the United Nations, it said on Monday.
Guterres was Portugal's prime minister between 1995 and 2002 and served two terms as UN high commissioner from 2005 until last year.
"With this step, Portugal actively contributes to the selection process by presenting a candidate who is exceptionally well qualified to be the next Secretary-General of the United Nations," the prime minister's office said in a statement.
It said the prime minister wrote on Monday to the presidents of the UN General Assembly and Security Council to formally submit Guterres' candidacy.
Guterres led UNHCR at the beginning of the refugee crisis caused by the war in Syria, which is posing increasing challenges for Europe.
The current UN secretary-general, Ban Ki moon, took office in January 2007 and is due to serve until the end of 2016.