Simonovic noted that media workers in Ukraine are endangered not only in the zone of armed conflict between government forces and independence supporters, citing the recent murder of opposition journalist Oles Buzina.
The UN official stressed that Buzina was a critic of the current Ukrainian government adding that it is still unclear who is responsible for his murder.
Buzina, 45, was shot dead in April in Kiev by two masked gunmen. His murder was preceded by the killings of two other opposition figures, Serhiy Suhobok and Oleh Kalashnikov, also known for their criticism of current Ukrainian leadership.
During the conflict in southeastern Ukraine, which began in April 2014, dozens of journalists have been killed, injured or come under fire.
Rossiya Segodnya news agency's photo correspondent Andrei Stenin, Channel 1 cameraman Anatoly Klyan, Rossiya TV network correspondent Igor Kornelyuk and sound engineer Anton Voloshin were killed while on duty in eastern Ukraine in 2014. Each of them were posthumously awarded the Order of Courage in Russia.