Rod Rosenstein, Donald Trump's deputy attorney general who oversees the Russia investigation, was headed Monday to the White House with the expectation of being fired, US media reported.

Several media including The New York Times and The Washington Post reported that Rosenstein was preparing to be dismissed, following the publication of reports that he had discussed ways to remove Trump over incompetence.

It was not immediately clear whether he would be sacked, or would resign first.

Rosenstein plays a key role in overseeing the probe by Special Counsel Robert Mueller into whether Trump's campaign colluded with Russia to influence the 2016 election.