The United States finished just above Senegal and just below Romania on this year’s list.

It also fell into the ranks of countries whose treatment of journalists is considered “problematic,” the first time the United States has been so classified since the organization began the index in 2002.

The top ranks were dominated once again by European countries: Norway ranked first for the third time in a row, followed by Finland, Sweden, Netherlands and Denmark. The bottom of the list included, in descending order, Vietnam, China, Eritrea, North Korea and Turkmenistan.

The group cited both Trump’s rhetorical hostility toward the American news media and a possibly related phenomenon — increasing threats of harm against reporters — for the nation’s declining status.

It noted that “hatred of the media” reached the point where a gunman killed four journalists and another employee at the Capital Gazette newspaper in Annapolis in June.

“Amid one of the American journalism community’s darkest moments, President Trump continued to spout his notorious anti-press rhetoric, disparaging and attacking the media at a national level,” it said. “Simultaneously, journalists across the country reported terrifying harassment and death threats, online and in person, that were particularly abusive toward women and journalists of color.”

Journalists were also murdered last year in Malta, Mexico, Bulgaria, Slovakia and Ghana. Perhaps most infamously, Washington Post columnist Jamal Khashoggi, a Saudi Arabian dissident, was murdered by government operatives in the Saudi consulate in Istanbul last fall — a homicide that “sent a chilling message to journalists well beyond the borders of Saudi Arabia.”

Violence against journalists is routine in some parts of the world, as are campaigns of government intimidation and online harassment, the group said. It said only 24 percent of the nations in its survey could be classified as “good” or “fairly good” in their treatment of the press, a slight decline from last year.

The greatest regional deterioration worldwide, it said, was in the Americas, led by the decline of the United States, Nicaragua, Venezuela, Mexico and Brazil. Brazil recently elected a new president, conservative Jair Bolsonaro, who is sometimes called “the Trump of the Tropics” for his disparagement of political opponents, women and gay people and his frequent verbal attacks on Brazil’s news media.