The Federalist, the Epoch Times, and One America News signed the Defense Department's press rules. The rest are freelancers, independent or work for media outfits based overseas.
The rare act of protest comes as Russia has cracked down on the arts, forcing out those who disagree with its war on Ukraine and quashing any acts of dissent.
Debate is raging across Europe over whether governments have overreached in restricting hate speech, but criticism from President Trump is seen as hypocritical.