In an interview with AFP, the Organization for Security and Cooperation in Europe's press freedom advocate, Dunja Mijatovic, said that rights groups were slow to react at the start of the crisis, before mass protests toppled President Viktor Yanukovych's government.
"Now the situation is different but if you look at when the crisis started in December with these first attacks on (the) Maidan (square) on more than 40 journalists, we were quite lonely in that period."
"It's killing the cause because a joint voice coming from international organisations could help," she said on Tuesday, ahead of the publication Thursday of her biannual report taking stock of the media freedom situation in Europe, North America and central Asia.
In the last few months, journalists covering the spiralling unrest in Ukraine have repeatedly been the target of harassment, beatings and kidnappings.
On Tuesday, two members of a Russian television crew were killed in the ex-Soviet state's separatist east after being caught in an attack by Ukrainian forces.
The deaths of journalist Igor Kornelyuk and sound technician Anton Voloshin brings the number of journalists killed in Ukraine since the start of the year to five, according to Reporters Without Borders.
In May, Italian photographer Andrea Rocchelli and his assistant Andrei Mironov were killed by mortar fire in eastern Ukraine.
Their deaths followed the killing in February of a 32-year-old Ukrainian reporter Vyacheslav Veremiy in Kiev by suspected pro-Yanukovych protesters.
'Orgy of violence'
Since the start of the unrest, there has been "an orgy of violence perpetrated on members of the media," Mijatovic said in the report.
The UN Security Council quickly condemned this week's deaths, calling for an investigation into violence against journalists in Ukraine and expressing concern about the detention and harassment of reporters.
Often, however, UN and European rights bodies were tied up by procedure and the need to get member states' approval before taking action, "and then they are slower than they should be in addressing certain issues," Mijatovic told AFP.
"It's disappointing," she concluded, also pointing to the initial lack of condemnation from media groups and the European Union after Hungary's Prime Minister Viktor Orban began imposing strict curbs on the press in 2010.
"There are never too many voices when it comes to defending media freedom and journalists' safety around the world, because it's needed."
Although its successes have remained low-profile, OSCE interventions have helped loosen media restrictions and secure the release of jailed journalists throughout the region -- such as in Belarus where there is "not one single journalist challenged now because of the work they did" -- she said.
But there was still a long way to go to guarantee media freedom in the OSCE's 57 members states -- which range from the US and Finland to Turkey and Tajikistan.
"To my great regret the situation in relation to media freedom is ... decreasing in too many countries in my view, particularly when we talk about the safety of journalists," said Mijatovic.