Helen Clark is heading into uncharted territory, entering the first open contest to become the world's most important international diplomat.
The eight nominations to date as Secretary-General of the United Nations could be boosted by at least two between now and the open sessions between candidates.
Argentine Foreign Minister Susana Malcorra is rumoured to be ready to announce her candidacy.
A respected former top aide to current Secretary-General Ban Ki-moon, she would be a strong rival for Helen Clark in the event that a consensus cannot be found around an Eastern European candidate.
Her decision is also likely to put pressure on former Australian Prime Minister Kevin Rudd to declare whether he wants to run for the job or not.
Prime Minister John Key held nothing back in his praise yesterday in nominating the former Prime Minister and former rival for the job.
He said she had dedicated her life to foreign policy and had the intellect and skills to be the best person for the job.
Helen Clark said the UN Secretary-General needed to have great patience, and to be a tolerant and respectful person.
"I think New Zealand exhibits that in the way it behaves and I like to think those are attributes I have," she told the Herald from New York.
She will clear her diary for an intense campaign over the next few months involving travel for her, ministers, special envoys and foreign affairs officials to world capitals.
Mr Key will also press her case in a pre-scheduled visit to China this month.
One of the most important events in the campaign takes place next week in New York.
That is when Helen Clark will appear in an open individual session of the UN General Assembly to put her case and answer questions about her candidacy.
There are no other formal events at the UN but Helen Clark suggested there may be other public forums featuring candidates. She told the Herald she would like the 70-year-old organisation to adapt to the changing nature of armed conflict which tended not to be between countries but was the result of civil war and violent extremism.
That could mean more pre-emptive action from the UN.
"This is a world with many, many complex peace and security challenges and I think the whole UN orchestra has to play as one across the humanitarian, development, peace-building, political and human rights pillars to try to ward off these kind of crises, act pre-emptively, use pro-active diplomacy and really urge our member states to make the long-term investment in the peaceful and inclusive societies which talk through their differences rather than fight them out."
Russia's position could be crucial and while its UN ambassador has said publicly it wants an Eastern European candidate, Helen Clark said she had developed a very good relationship with Russia as head of the non-political UN Development Programme.
Under UN rules, the appointment of the Secretary- General is made by the General Assembly on the Security Council's recommendation.
Kiwis, 'use your voice'
Helen Clark has asked New Zealanders to use their voices to support her bid to become the next Secretary- General of the United Nations.
And the best way to be heard would be through social media, Facebook, Twitter - "just really, really pushing it out there".
"People say 'what can I do? I'm sitting here in Kaitaia. What can I do?' You've got a voice; use your voice," she told the Herald yesterday.
Twitter was almost unheard of when incumbent Ban Ki-moon was appointed in 2006, and she said social media would be one of the features that would make the campaign unique.
Soon after confirming her nomination for Secretary-General, she launched a campaign Twitter account @Helen4SG
"I do intend to run an accessible campaign and I look forward to engaging with the General Assembly next week and with the broader public in the weeks ahead."
Husband ready to live in NY
Helen Clark and husband Peter Davis have lived at other ends of the world for the past seven years, but if Clark gets the Secretary-General role he is ready to move to New York with her.
When Helen Clark moved in 2009 to take up the role as head of the UN Development Programme, Dr Davis decided to stay as professor of sociology at the University of Auckland.
However, the Secretary-General role would mean Helen Clark was in New York for at least another five years and up to a decade if her term was renewed as it has been for most previous Secretary-Generals.
Dr Davis said his wife should get the role and stay in New York. "The truth is she's got talent to spare and as long as she's got the will and the energy she should still continue trying to do these useful types of jobs.
"This is a good opportunity for me to go and join her. Regardless of what happens, whatever she does ... it's getting to the stage where frankly you should start to be spending a bit more time together."
He had visited New York and Helen Clark returned to New Zealand often, partly to visit her father George, who was in his 90s.
Dr Davis did not know what he might do in New York but an honorary role at a university was possible if UN rules allowed it.
Dr Davis said Helen Clark had told him of her decision when she visited over Easter. He did not expect to play a role in her campaign but will be in New York for moral support next week when she and the other candidates have to give their pitches to the General Assembly.