Mr Jones quit Parliament to accept a Government post as New Zealand's first Pacific Economic Ambassador and has been in Washington at an Oceans conference hosted by Mr Kerry.
Mr Jones said when he made his decision to leave politics he was conscious of Labour's "June drop dead date".
That was a reference to Labour Party rule that would allow the caucus to depose a leader and elect a new one without reference to the wider membership.
Mr Cunliffe won the majority of his support from party members, not the caucus, and has implied that any move against him would be carried out by "scabs".
Mr Jones wouldn't comment on the use of the term.
"You cant draw me on that," he told reporters travelling with Mr Key.
"Those of us who were in politics, we practice hyperbole. I'm no longer in that scene and the purveyors of that rhetoric, they can stand up for themselves."
He denied being the source of media stories about Donghua Liu's donations to Labour, lavish hospitality in China by Mr Liu on Labour MPs, and Mr Cunliffe's assistance to him in gaining residency.
"That is a total lie."
"I have not had anything to do with whatever is happening in respect of the media coverage of Labour Party issues at the moment."
He said he had never met Mr Liu or been to his Epsom property development.
"I have never been to China since 2005 and ... I didn't meet that man."
Mr Jones said he was still a member of the Labour Party.
