Dumped treasurer Joe Hockey will become Australia's ambassador to the United States in the new year, and has conceded staying in parliament would have been about "getting even" with those who engineered his downfall.

Foreign Minister Julie Bishop has confirmed the widely anticipated news that the former treasurer will take over the Washington post from Kim Beazley in January.

Mr Hockey, 50, announced his retirement from politics after being ditched as treasurer by Mr Turnbull in September.

In a rare post-politics interview, Mr Hockey conceded that if he had stayed in parliament he would have been seeking retribution for his ousting.

The interview, filmed in the back of a Sydney coffee shop, was conducted with Australian businessman Mark Bouris for his online television show.

"The politics, at the end of the day, beat me," Mr Hockey said.

"If I was going to stay it'd have to be, it'd be overwhelmingly about getting even with people that brought me down.

"I love my country and my family more than I hate my enemies."

Mr Hockey said he wanted to look forward rather than "reflecting too much on what happened" and still wanted to contribute to the nation.

This morning Mr Turnbull heaped praised on Mr Hockey and outlined his credentials for the role.

"Joe is a great Australian, he is one of the most engaging, persuasive people I've known in public life," Mr Turnbull said.

"He's held very high office, he's got great contacts in the United States, he's a passionate patriot but [has] a good understanding of how Washington works already."

But the Federal Opposition has raised doubts about the ongoing working relationship between the pair, and the potential for diplomatic ramifications.

"Clearly, Malcolm Turnbull only a few weeks ago tore down Tony Abbott and Joe Hockey," Labor frontbencher Brendan O'Connor told Sky this morning.

"I'm concerned that the relationship is still a reasonable one, because if it's not, we're going to have some problems in our relationship with our biggest allies."

When Mr Turnbull launched his successful challenge for the prime ministership in September he told reporters, "the Government is not successful in providing the economic leadership that we need".

At the time Mr Hockey responded by defending the Government's economic record and railed against detractors, saying "the disloyalty of some has been outrageous".