Trump this week blasted the Russia investigation as "never ending and corrupt."

The poll was conducted Sunday to Wednesday, with interviews overlapping the FBI's Monday raid of the home and office of Michael Cohen, Trump's longtime attorney. Agents seized communications between Cohen and Trump, as well as records related to a 2016 payment Cohen made to adult-film star Stormy Daniels, who claims to have had a sexual encounter with Trump. The Cohen inquiry was opened by the Manhattan-based US attorney's office following a referral from Mueller.

Mueller was appointed to investigate any links between the Trump campaign and Russia, as well as any other matter directly arising from that probe. While Mueller has subpoenaed Trump Organisation documents related to business activities in Russia, there has so far been no confirmation that his investigation has expanded to cover Trump business activities that do not relate to Russia. There is also no indication that Mueller's team is exploring accusations by women about Trump's personal conduct.

Trump's firing of FBI Director James Comey in May has also been probed by Mueller and is receiving renewed attention with the release next week of Comey's book and several media interviews surrounding its publication.

The Post-ABC poll finds Americans' views of Comey include division and indifference, with 3 in 10 seeing him favourably, just over 3 in 10 unfavourably and the rest offering no opinion. But by 48 per cent to 32 per cent, Comey is seen as more believable than Trump, and adults disapprove of Comey's firing by a similar margin, though a sizable share chose neither or had no opinion.