Donald Trump’s attacks on the media have been condemned by experts at the United Nations, who warned that the US president’s vitriolic rhetoric could result in violence against journalists.

In a joint statement, two experts on freedom of expression – David Kaye, who was appointed by the UN human rights council, and Edison Lanza, who holds the corresponding position at the Inter-American Commission on Human Rights, said: “These attacks run counter to the country’s obligations to respect press freedom and international human rights law.”

Trump’s attacks “are strategic, designed to undermine confidence in reporting and raise doubts about verifiable facts”, they added, while noting the president “has failed to show even once that specific reporting has been driven by any untoward motivations”.

“We are especially concerned that these attacks increase the risk of journalists being targeted with violence.”

The rebuke comes as Trump has intensified his criticism of the media and appeared to embrace the hostile attitude among his supporters towards members of the press.

The president unleashed a Twitter tirade against the media on Sunday, labeling reporters as “unpatriotic”.

“When the media – driven insane by their Trump Derangement Syndrome – reveals internal deliberations of our government, it truly puts the lives of many, not just journalists, at risk! Very unpatriotic!” Trump tweeted.

“Freedom of the press also comes with a responsibility to report the news … ...accurately,” he added. “90% of media coverage of my Administration is negative, despite the tremendously positive results we are achieving, it’s no surprise that confidence in the media is at an all time low!”

Earlier this week, the president and his son, Eric Trump, shared a video on their Twitter accounts of attendees at a Trump rally in Tampa, Florida, shouting “CNN sucks!” at journalists covering the event.

The taunts came a week after the White House was roundly criticized for banning the CNN reporter Kaitlan Collins from covering an event that was open to the press after she had repeatedly directed questions to the president about his relationship with his former attorney, Michael Cohen.

Trump’s combative approach toward the media has been emblematic of both his tenure in the White House and candidacy for president; in 2016, the Trump campaign routinely barred media outlets from covering rallies in retaliation against coverage of which they disapproved.

Trump has often used his podium to hurl insults at the press and single out reporters by name, frequently before an angry mob of his supporters, and has derided coverage he dislikes as “fake news”.

The president has also labeled the media the “enemy of the American people” – a characterization his daughter, Ivanka Trump, rejected on Thursday.

“I’ve certainly received my fair share of reporting on me personally that I know not to be fully accurate, so I have some sensitivity around why people have concerns and gripe, especially when they’re sort of targeted,” she said at an event hosted by Axios.

“But no, I do not feel that the media is the enemy of the people.”

The issue also arose during a fraught exchange at Thursday’s White House briefing. Press secretary Sarah Sanders produced a list of complaints about how she has been personally “attacked” by the media, including comedian Michelle Wolf’s mockery of her at this year’s White House correspondents’ dinner.

Sarah Sanders at the White House on Thursday. Photograph: Nicholas Kamm/AFP/Getty Images

“You brought a comedian up to attack my appearance and call me a traitor to my own gender,” Sanders said, becoming visibly emotional. “As far as I know, I’m the first press secretary in the history of the United States that’s required secret service protection.”

But Jim Acosta, the CNN journalist heckled at the Tampa rally, repeatedly challenged Sanders to publicly disagree with Trump’s view of the press as the enemy of the people.

Sanders replied: “I appreciate your passion. I share it. I’ve addressed this question. I’ve addressed my personal feelings. I’m here to speak on behalf of the president. He’s made his comments clear.”

Acosta then tweeted: “I walked out of the end of that briefing because I am totally saddened by what just happened. Sarah Sanders was repeatedly given a chance to say the press is not the enemy and she wouldn’t do it. Shameful.”