Presumptive U.S. Republican presidential nominee Donald Trump took the unprecedented step Monday of denying press access to The Washington Post, one of the United States' most influential newspapers.

Citing what it called unfair coverage, the Trump campaign wrote in a Facebook post that it was revoking the press credentials of the "phony and dishonest Washington Post."

"The Washington Post unfortunately covers Mr. Trump very inaccurately," the Trump campaign said in a statement posted to its website.

"We no longer feel compelled to work with a publication which has put its need for 'clicks' above journalistic integrity," it said. "Mr. Trump does not mind a bad story, but it has to be honest."

It is extremely unusual for a presidential campaign to refuse to issue credentials to news organizations. Such credentials are required for reporters and other staff to gain access to seating, travel on the road with the campaign and attend media-only events such as news conferences.

According to the Post, editors were unsure what the ban entails, and had not had contact with the Trump campaign over the issue as of Monday evening.

In a statement, Post Executive Editor Martin Baron said: "Donald Trump's decision to revoke The Washington Post's press credentials is nothing less than a repudiation of the role of a free and independent press. When coverage doesn't correspond to what the candidate wants it to be, then a news organization is banished.

"The Post will continue to cover Donald Trump as it has all along — honorably, honestly, accurately, energetically and unflinchingly," Baron continued. "We're proud of our coverage, and we're going to keep at it."

Trump has clashed with the press before, and the row with the Post is only the latest in a series of bans unleashed by his campaign. But Trump has mainly targeted individual reporters, not organizations as a whole.

According to the Post, the campaign has at times blacklisted reporters from the following news organizations: Gawker, BuzzFeed, Foreign Policy, Politico, Fusion, Univision, Mother Jones, the New Hampshire Union Leader, the Des Moines Register, the Daily Beast and the Huffington Post.

Critics of the latest ban, including the Committee to Protect Journalists, issued a scathing condemnation of the move.

"A candidate for the highest elected office in the land doesn't get to choose what goes in a newspaper," CPJ Deputy Executive Director Robert Mahoney said in a statement Monday.

"Revoking the credentials of The Washington Post to cover the Trump campaign is bad for voters in the United States and bad for press freedom everywhere," the statement said. "It provides a ready-made excuse for authoritarian leaders to crack down further on independent journalists. We urge Donald Trump to reconsider and let The Washington Post do its job."