Donald Trump has blocked the release of a Democratic rebuttal to a Republican memo alleging bias against the US president over the FBI’s Russia probe.

The White House said on Friday Mr Trump could not declassify the memo because of “sensitive passages” that create “concerns for national security”.

A congressional panel this week voted unanimously to release the document.

Democrats say their memo contains corrections to errors and omissions in the Republican document.

• Key parts of Republican memo – and what it means

Last week, Mr Trump defied warnings from the FBI to release a Republican document that alleged the agency had abused its power by investigating a Trump adviser as part of its probe into Russian interference in the 2016 presidential election.

Democrats argued that the memo cherry-picked information and was misleading.

On Monday, the House of Representatives Intelligence Committee voted unanimously to declassify the 10-page Democratic memo, which aimed to counter the Republican document.

Adam Schiff, who wrote the second memo, said at the time that Republicans had “found themselves in an insupportable position when they released a misleading memo and refused to release the Democratic response”.

Democratic Senate leader Chuck Schumer said it was a matter of “fundamental fairness” the memo be declassified, urging the president to demonstrate he was not trying to undermine the Russia investigation.

But in a letter to the committee’s chairman, White House Counsel Don McGahn said Mr Trump had decided against approving public release of the Democratic memo “because the memorandum contains numerous properly classified passages”.

A separate letter, from FBI chief Christopher Wray and Deputy Attorney General Rod Rosenstein, also said releasing the memo would create national security concerns.