Helen Clark, the former prime minister of New Zealand, has entered the race to succeed Ban Ki-moon as secretary general of the United Nations in a bid to become the first woman in the role of world’s top diplomat.

Clark, who was New Zealand’s prime minister from 1999 to 2008, threw her hat formally into the ring on Monday. Her high-profile entry into the competition is certain to increase pressure among the power brokers of the UN to appoint a woman as the leading face of diplomacy on the global stage.

Announcing her candidacy in New York shortly after she was nominated for the top post by New Zealand’s current prime minister, John Key, in Wellington, Clark said she believed she had the skills to lead the UN as it faced “very serious challenges”.