Helen Clark says she is "deeply honoured" to be nominated by the New Zealand Government for the role of United Nations Secretary-General.
Prime Minister John Key confirmed her nomination for the UN's top job at a news conference in Wellington this morning.
Miss Clark, the head of the United Nations Development Programme, announced her bid in New York this morning (NZ time). She is the eighth candidate to enter the contest.
In a statement today she said: "To receive the full backing of the New Zealand Government is a great honour. New Zealand has a proud history of supporting the United Nations from its very beginning. We, New Zealanders, have developed our own way of getting along with one another and getting things done.
"The tradition of being tolerant, pragmatic, and fair is a central part of who we are, and I believe I would bring these attributes to the position of Secretary-General."
Speaking to reporters at the Beehive, Mr Key said Miss Clark was "the best person for the job".
Having served as New Zealand's Prime Minister for nine years and one of the top UN roles for seven, she had the right mix of skills and experience, he said.
Mr Key said the UN needed a proven leader to tackle the major global challenges the world was facing.
"Coming from New Zealand, Helen Clark is well placed to bridge divisions and get results. She is the best person for the job."
The Prime Minister said Miss Clark clearly had the most experience out of the Secretary-General candidates, but he said there was "a lot of horse trading" in choosing the next UN leader. He said he lobbied global leaders during a visit to Washington last week, and directly raised her candidacy with US President Barack Obama.
The New Zealand Government would spend "hundreds of thousands" in supporting her bid. Mr Key said he did not get any "push back" from the US when he discussed her bid.
It was difficult to choose a frontrunner, because the process was highly politicised and complicated. The public should have a "degree of confidence and a degree of realism" about Miss Clark's chances, Mr Key said.
Mr Key and Foreign Minister Murray McCully are thought to have approved a high-level campaign and funding to support her bid.
If successful, Helen Clark will have 41,000 staff working for her worldwide. She will earn a tax-free base salary of about $US230,000 ($NZ338,000) as well as free accommodation in New York. However, the job has been described as the most difficult job in the world by the man who first held the role - Trygve Lie.
For the past seven years, Miss Clark been the head of the UN Development Programme, overseeing a global budget of $6 billion in 170 countries and a staff of 7500. She is on a base salary of about $US190,000 but her total remuneration has been estimated at $US450,000. She has previously said a "significant portion" of that goes toward paying for her New York apartment.
Mr Key, who defeated her to become Prime Minister in 2008, has been unstinting in his praise of her capability, and that continued yesterday at his post-Cabinet news conference. "I've said to anyone who has asked me that Helen Clark would be a great Secretary-General of the United Nations."
Asked if it would be hard promoting a political rival, he said they had competed when he was Leader of the Opposition and she was Prime Minister.
"But there's a mature point at which you put politics to one side and you acknowledge and hopefully celebrate the skills of a New Zealander, not because of their political tendencies but because of their ability and capacity to do a job," he said.
"Personally, I think if Helen becomes the next Sec-Gen of the United Nations, New Zealanders would celebrate in the same way they celebrate Lorde for her achievement in singing and Lydia Ko in golf and so many other New Zealanders in what we do."
Mr Key said he would do everything he could to get her over the line, but people had to realistic about their expectations.
"Whatever happens, this is going to be a highly contested campaign and there's a lot of politics involved."
He thought she could do immensely well in the job. "But I also thought, myself, that Tim Groser was the best to head the WTO [World Trade Organisation] and he didn't get that."
Eastern Europe bid
Most of the other seven candidates for the job are from Eastern Europe, which has never held the post before. If the appointment continued to be determined by geographic rotation, then it would be considered to be Eastern Europe's turn.
But the 70-year-old UN is being pressed in some quarters to appoint its first woman head and to dispense with the geographic rotation.
Russia will be critical. It has publicly said it expects the next Secretary-General to come from Eastern Europe and it has a veto, along with the other four permanent members of the Security Council - the United States, China, Britain and France.
With the UN General Assembly scheduled to hold a candidates' forum on April 13, Miss Clark has been under the clock to declare her hand.
Under UN rules, the decision is made by the General Assembly on the recommendation of the Security Council.
Miss Clark's chances would be good if the Eastern Europe countries, including Russia, failed to unite around a candidate - or if a candidate around which they united was unacceptable to other permanent members of the Security Council.
Helen Clark's statement
"I'm very, very honoured to receive the full backing of the New Zealand Government and by all the correspondence and traffic coming in, enormous support from the people of New Zealand.
"New Zealand is a Pacific nation of great diversity, situated in a region of great diversity. New Zealanders have developed over time, our own way of getting along with each other and getting things done. The tradition of being tolerant, pragmatic and fair is part of who we are.
"I'm running for Secretary-General because I believe that with this background, I can offer the style of leadership which is needed today. And which will help the United Nations meet the very serious challenges which lie ahead.
"As one of the longest serving Prime Ministers of New Zealand, and now having been Leader of UNDP and Chair of the UN Development Group these past seven years, I believe I am the right person for the job.
"New Zealand as this Pacific nation has a proud history of support for the United Nations, right from the very beginning of the drafting of the Charter. We need a UN which is up to the task of tackling the major challenges facing our world today and I believe I am the leader that is up to the task of leading the organisation. I want to do it because I am deeply committed to the ideals of the UN Charter and have supported it my whole adult life.
"At its best, the position of UN Secretary-General is about giving a voice for the world's seven billion plus people who look to the UN for hope and support and inspiration.
"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. I will obviously be talking in more detail about the vision that I have for the organisation and my priorities in the coming period which I anticipate will be for quite some months."
Rudd puts transtasman contest in play
The stealth campaign by former Australian Prime Minister Kevin Rudd for the job as Secretary General was revealed by Australian Foreign Minister Julie Bishop at the weekend.
Mr Rudd has avoided any confirmation he wants the job. But Ms Bishop told reporters in Washington DC, covering her attendance at the Nuclear Security Summit, that several leaders had mentioned Mr Rudd's interest.
"It seems that Mr Rudd has visited a number of people and expressed an interest," she said.
He had not yet formally asked the Australian Government for support.
Asked if they were talking about supporting Mr Rudd, she said: "No, they were talking about the number of potential candidates."
A transtasman contest could come into play if no consensus candidate from Eastern Europe emerged.
Mr Rudd's candidacy has raised eyebrows given his record in politics. He was elected Prime Minister in 2007 but was ditched by his own party part way through the first term. After finally regaining the position from Julia Gillard near the end of Labor's second term, he was beaten at the polling booth by Liberal leader Tony Abbott, who has since been deposed by Malcolm Turnbull.
In order to avoid having to support a Rudd candidacy, Mr Abbott arranged for the Australian Government to privately commit in writing to supporting any Helen Clark bid, in the event she decided to declare. However, he did not consult Ms Bishop and the pledge was revealed only after Mr Turnbull had deposed Mr Abbott - much to Ms Bishop's annoyance.
Many pundits in Australia believe the Australian Government would have to support a bid by Mr Rudd, were he to formally declare and seek it. That would prevent Australia actively campaigning for Helen Clark who is considered to have a much stronger chance than Mr Rudd because of her track record, and her gender.
But some pundits have said it should support any bid by Miss Clark.
Mr Rudd had a famously short fuse and in one of his tantrums, at the Copenhagen climate change conference, described the Chinese as "rat f**kers."
- additional reporting by Audrey Young