Former Australian prime minister Tony Abbott's commitment to back Helen Clark for the job of UN Secretary-General may be forgotten if Kevin Rudd seeks the role.
Australian Foreign Minister Julie Bishop has signalled the government would consider supporting Mr Rudd, a former Australian Labor prime minister, if he was nominated for the UN job and if no firm commitment had been given to anyone else.
But an exchange of letters obtained by The Australian newspaper revealed Mr Abbott committed to a joint plan with New Zealand Prime Minister John Key to back Ms Clark to succeed Ban Ki-moon.
Ms Bishop told reporters that nominations for the UN job had only just opened and the government had yet to consider the full field of candidates
But Ms Bishop said Mr Key recently made it clear that New Zealand did not expect Australia to be bound by any commitment that Mr Abbott made to him.
"The position as far as I'm concerned has always been, and remains, that the Australian government would consider the full field of candidates for this job once that was known," she said.
She said a final decision about whether to support a candidate for the UN job or not would be made by cabinet.
"The field, as far as I'm concerned, is wide open."
Nominations for the job opened in December. Ms Clark, who heads the UN's development programme - making her the third highest ranking person at the UN - has never commented publicly on whether she wants the top job of secretary-general.
But Ms Clark has been quoted as saying there would probably be some expectation that the ninth person to lead the UN will be a woman.
Until recently, the selection of the UN secretary-general has been the decision of the five permanent Security Council members - Britain, France, Russia, China and the United States.
This year, the UN said, all 193 member states will for the first time be included "totally" in the selection, it encouraged member states to "consider presenting women, as well as men" as candidates.
In 2016, all countries will get the opportunity to openly interview candidates.
- AAP / RNZ