On the other side of the Atlantic, US President Donald Trump has refused to declassify a high-profile memo written by Democratic lawmakers about the Russia probe.

The White House said the Justice Department had identified portions of the memo that would create especially significant concerns for the national security and law enforcement interests of the country. The Democrats' memo aimed to counter a Republican-drafted one that the president declassified and released earlier this month. According to the Republican-drafted memo, a number of top US law enforcement leaders abused their power by inappropriately obtaining a surveillance warrant on Carter Page, a foreign policy adviser to the Trump presidential campaign until September 2016.