Talks between Australia and New Zealand over the United Nations Secretary Generalship look set to be informal for the time being.

Former Kiwi Prime Minister Helen Clark is speculated to be interested in the job, and so too is ex-Australian Prime Minister Kevin Rudd.

Previous Australian PM Tony Abbott had endorsed Clark for the job, but that deal's no longer on the table after he was rolled by Malcolm Turnbull.

Foreign Minister Murray McCully says this is an area where they don't know what the landscape is going to look like, "but I guess informally we'll certainly have that discussion."

"Whether we have it more formally will depend on developments."