Kevin Rudd has said another country offered to nominate him for the top job at the United Nations after the Turnbull government knocked back his bid.

But the former prime minister said through his spokeswoman on Sunday that he ruled out the proposed nomination from the unnamed country after asking the Australian government its view and failing to receive a reply after more than six weeks.

Former prime minister Kevin Rudd says another country offered to nominate him for UN Secretary General. Credit:Alex Ellinghausen

"Following the decision by the Australian government, another government approached Mr Rudd to nominate him as a candidate for UN Secretary General," the spokeswoman said.

"Mr Rudd approached the Australian government more than six weeks ago asking if they would oppose such a nomination, were he to consider accepting it.