Ressa heads Rappler, a digital media company which she co-founded in 2012, and which has grown prominent through investigative reporting, including into large scale killings during a police campaign against drugs.
"I am in shock," Ressa told a live broadcast by Rappler.
In August, a Philippine court dismissed a libel case against Ressa, one of several lawsuits filed against the journalist who says she has been targeted because of her news site's critical reports on President Rodrigo Duterte.
The plight of Ressa, one of several journalists named Time Magazine Person of the Year in 2018 for fighting media intimidation, has raised international concern about the harassment of media in the Philippines, a country once seen as a standard bearer for press freedom in Asia.