White House hunts leaker after Trump congratulates Putin
US President Donald Trump (right) and Russia's President Vladimir Putin talk during the Asia-Pacific Economic Cooperation (APEC) leaders' summit in the central Vietnamese city of Danang on November 11, 2017 (AFP Photo/JORGE SILVA)

The White House fumed Wednesday about an embarrassing leak of Donald Trump's shock decision to congratulate Vladimir Putin on his re-election, with one official describing the disclosure as illegal.

A hunt is underway to find the person who leaked Trump's prepared notes for the call, which included a warning "DO NOT CONGRATULATE," which he ignored.

Trump had shunned the advice of some aides in making the call Putin at all.

He then went a step further to congratulate the Russian leader on winning a fourth presidential term, despite the election being plagued by evidence of ballot stuffing, media censorship and the jailing of political opponents.

The Washington Post and others reported that staff explicitly advised Trump not to congratulate Putin and that he should condemn the poisoning of a former Russian spy in Britain.

According to accounts from the White House and the Kremlin, Trump did neither.

The leak of such sensitive information about Oval Office deliberations points to deep frustration within the White House about his ad-hoc approach and disregard for the advice of his inner circle.

Very few officials would have known about the details of the call, only those at the very highest levels of the administration and the president himself.

Officials, speaking on condition of anonymity, told AFP that the hunt for the leaker was underway.

One official suggested the documents preparing for the call may have been classified, making unauthorized disclosure a crime.

"We cannot comment on alleged classified deliberative documents allegedly provided to the president" a senior administration official told AFP.

The leak was undoubtedly damaging for a White House already in disarray.

Allies, most notably in Britain, were furious about Trump's lack of solidarity after a chemical weapons attack on double agent Sergei Skripal in a small English town.

The White House waited for days before condemning the attack, which London has pinned squarely on the Kremlin and Moscow has denied.

The White House leak also compounded a major diplomatic victory for Moscow, offering Putin legitimacy while giving him a wedge to drive between western allies and within the White House itself.

Republicans in Washington were critical of Trump's decision to congratulate Putin, but also lined up behind the president in anger about the leak.

"I don't like that he did it, but you know what I like even less? That there is somebody close to him leaking this stuff out. If you don't like the guy, quit!" said Republican Senator Marco Rubio.