Cabinet to decide on Rudd UN support: PM

Prime Minister Malcolm Turnbull says cabinet will decide whether to support Kevin Rudd for UN secretary general, if he decides to nominate.

Malcolm Turnbull says cabinet will decide whether to support Kevin Rudd for the top job at the UN. (AAP)

Malcolm Turnbull says his cabinet will decide whether to support Kevin Rudd for the top job at the United Nations.

While Mr Rudd has yet to formally throw his hat in the ring for secretary-general, a role which becomes vacant later this year, there are reports he's quietly lobbying for support behind the scenes.

"If Mr Rudd does nominate, then the cabinet will consider the matter and consider how we would approach it," the prime minister told Radio 3AW on Friday.