U.S. President Donald Trump's attacks on the media are part of a global trend of hostility to freedom of speech and damage the U.S. public interest, a U.N. human rights expert said Friday.

David Kaye, the U.N. special rapporteur on the freedom of expression, said Trump's attacks, such as a Feb. 17 tweet listing news outlets that he considered "the enemy of the American People," were not without purpose.

"They have concrete aims: to intimidate reporters into certain kinds of coverage, or clarify for his favored outlets what coverage he desires, or plant the seeds of doubt about news stories (such as the Russia investigation led by Robert Mueller)."