UNITED NATIONS — On World Press Freedom Day when the U.N. chief was touting the "invaluable" role of a free press, a U.N. panel discussion on international media freedom and fake news was suddenly postponed, sparking accusations of censorship.

The postponement was raised at Thursday's official U.N. event marking World Press Freedom Day, where Secretary-General Antonio Guterres said in a video message that the service of the media to the public "is invaluable."

Robert Mahoney, deputy executive director of the Committee to Protect Journalists thanked organizers of the official event for shining a light on the work of journalists — but said unfortunately "as we battle censorship around the world ... the panel was cancelled because one of the presenters was going to mention by name countries that jail journalists."

"So we have a discussion in the U.N. about battling censorship, being censored, that's quite ironic," he said. "I would call on us all here present to resist the politicization — the increasing politicization of U.N. agencies whose mission is to defend press freedom."

The United Nations Alliance of Civilizations organized the panel which included about a dozen prominent journalists and media experts in collaboration with the News Literacy Project, an education nonprofit that works with educators and journalists to teach students how to sort fact from fiction in the digital age.

Alan Miller, the project's founder, said in a statement that the panel was postponed after his organization refused a request from the Alliance of Civilizations to remove references from a video it wanted to present to several countries that restrict press freedom including Turkey, Mexico, Egypt, Russia and Pakistan.

"I could not permit this censorship of our presentation due to the stated concern that it would offend one or more countries engaged in repression and violence against journalists," Miller said in a statement, adding that the video has since been posted on the project's website.

Farnaz Fassihi, a senior writer for the Wall Street Journal who was supposed to be on the panel, said at Thursday's U.N. briefing: "I've worked in all sorts of countries and I'm quite honestly shocked to have a panel canceled at the U.N. I mean, you expect it in other countries but not here."

U.N. deputy spokesman Farhan Haq responded saying: "We certainly believe that press should not be censored, and indeed no one who speaks at the U.N. should be censored for their views."

Nihal Saad, spokesperson for the Alliance of Civilizations, said the video was only submitted on Monday event and "we saw that it was unbalanced."

The alliance asked the group "to either make a comprehensive presentation of all countries where press freedom is limited, or to remove reference to specific countries that had been singled out in their report, to ensure objectivity and a more comprehensive presentation," she said in a statement late Thursday.

Saad said the panel was postponed because it was to be held at the same time as the official U.N. event and participation was lower than expected, including some last minute cancellations.

"Discussing issues regarding the freedom of the press and pointing fingers to particular countries — it's not useful," she told AP.

Saad said the Alliance of Civilizations has had five events with media experts from all over the world talking about issues relevant to freedom of expression including where to draw the line between free speech "and using your freedom responsibly."

She said all panelists will be invited to the new event which the Alliance is working to reschedule in late May or early June.