Sofia (AFP) - Bulgaria's foreign ministry on Tuesday formally announced its nomination of UNESCO chief Irina Bokova for UN secretary-general.

"The ministry of foreign affairs sent a letter, nominating Mrs Irina Georgieva Bokova for the post of secretary-general of the United Nations," the ministry said in a statement.

"Given her background and experience, Mrs Bokova may be one of the top candidates in the upcoming campaign for UN secretary-general," it added.

The UN's next chief will take up their post on January 1, 2017, replacing Ban Ki-moon who has held the job for two five-year terms.

Bulgaria's Bokova, 63, was the first woman to head the UN's culture body UNESCO, and the first leader from the ex-Soviet bloc when she was elected in 2009.

UNESCO's admission of Palestine as a member in October 2011 spelled problems for Bokova, with the United States immediately suspending its funding of the UN body.

But the former foreign minister won re-election nonetheless, and her second term is due to expire at the end of 2017.

"I know that I will win the UN vote," Bokova has confidently told private television channel Nova.

There has been much speculation over whether the UN will finally get its first female leader, after the eight men who have led the world body since 1946.

A former Bulgarian ambassador to France and Monaco, Bokova has recently been criticised over her privileged upbringing in a prominent communist family.

Her father Georgi Bokov was editor-in-chief of the Communist Party newspaper Rabotnichesko Delo.

Bokova received an elite education abroad, first at the Moscow State Institute of International Relations and later at the University of Maryland and Harvard in the United States.

After stints at the Bulgarian foreign ministry and its UN mission in New York, Bokova was elected a lawmaker for the Socialist Party after the fall of communism in 1989.

Bokova was appointed deputy foreign minister to coordinate Bulgaria's relations with the European Union between 1995 and 1997.

She briefly stepped up as foreign minister from November 1996 to February 1997 when she led the country's bid to join the EU.

She speaks fluent English, French, Russian and Spanish, and is married with two children.