France, May 2 -- Media rights group RSF on Friday warned about "an alarming deterioration in press freedom" in the United States under President Donald Trump as well as "unprecedented" difficulties for independent journalists around the world.

Paris-based Reporters Without Borders, which has been tracking press freedom for the last 23 years, said its main index had fallen to its lowest-ever level.

"For the first time in the history of the index, the conditions for practising journalism are poor in half of the world's countries and satisfactory in fewer than one in four," an annual review of media freedom globally by the charity concluded.

RSF editorial director Anne Bocande highlighted the role of economic pressures in undermining fact...