Obama made such a statement on the First-Annual International Day to End Impunity for Crimes Against Journalists.
History shows that a free press is a critical foundation for prosperous and open society, allowing citizens to access information and hold their governments accountable, said Obama.
"Each and every day, brave journalists make extraordinary risks to bring us stories we otherwise would not hear – exposing corruption, asking tough questions, or bearing witness to the dignity of innocent men, women and children suffering the horrors of war," says the statement of the president published on the official website of the White House.
The U.S. president expressed regret that "hundreds of journalists have been killed in the past decade alone, while countless more have been harassed, threatened, imprisoned, and tortured."
And in the overwhelming majority of these cases, the perpetrators of these crimes against journalists go unpunished, stressed Obama.
U.S. leader called on all the governments to "protect the ability of journalists to write and speak freely."
"On this first-ever International Day to End Impunity for Crimes against Journalists, the United States commends the priceless contributions by journalists to the freedom and security of us all, shining light into the darkness and giving voice to the voiceless," Obama said.
U.S. leaders also urged the world to demand accountability for those who have committed crimes against journalists.