Freedom House, a US-based human rights organization, highlighted growing concerns over efforts by governments around the world to clamp down on media and dissent.
"Political leaders and other partisan forces in many democracies -- including the United States, Poland, the Philippines and South Africa -- attacked the credibility of independent media and fact-based journalism, rejecting the traditional watchdog role of the press in free societies," said Jennifer Dunham, who headed the research.
The 2016 study of 199 countries concluded that just 13 percent of the world's population enjoys a "free press" with robust news coverage and protections for journalists.
Another 42 percent of the world's population has a "partly free" press and 45 percent live in countries where the media environment is "not free," the group said.
Friday's report echoed a similar survey released this week by France-based Reporters Without Borders, which said press freedom is facing serious threats in 72 countries, downgrading the rankings of the United States, Britain and others.
Freedom House said press rights are being eroded by the efforts of politicians in democratic states to shape news coverage and delegitimize media outlets.
"When politicians lambaste the media, it encourages their counterparts abroad to do the same," Freedom House president Michael Abramowitz said.
