Helen Clark, the former Prime Minister of New Zealand, has officially announced she is running for the UN Secretary-General's office.

Clark, who at the moment heads the UN Development Program, is seen as a strong rival to UNESCO Director General Irina Bokova. To date, the latter has been described as a "frontrunner" in the race.

The former PM (1999-2008) has told the BBC she would seek to expand the UN Security Council's permanent member seats if elected, including Germany, Japan, India, Brazil, and possibly two African states so that the body reflects the realities of "the 21st century world which we live in today," and not the one of 1945 it reflects now.

Despite the unofficial suggestions that Ban Ki-moon successor should come from Eastern Europe - no Secretary General has ever been elected from the region so far - there is a broader agreement only that the winning candidate should be female.

Yet, four men have also jointed the list of three (not counting Clark) women who have been officially endorsed by their states.

Candidates other than Bokova include Macedonia's ex-Foreign Minister Srgjan Kerim, Montenegro's incumbent FM and former interim PM Igor Luksic, former Croatian Foreign Minister Vesna Pusic, Slovenia's former President Danilo T?rk, Moldovan ex-Deputy PM and FM Natalia Gherman, and former Portuguese Prime Minister Antonio Guterres.