U.S. Secretary of State John Kerry is calling the release of European monitors taken captive by pro-Russian separatists in Ukraine a positive step, but says more is needed to de-escalate the situation.
Speaking Saturday in Kinshasa -- the capital of the Democratic Republic of Congo -- Kerry said it is important that Russia withdraw support for the separatists, who have seized a number of government buildings in eastern Ukraine.
Kerry made his comments after speaking by phone with Russian Foreign Minister Sergei Lavrov. The Russian foreign ministry says Lavrov told Kerry Saturday the U.S. should use its influence to make Ukraine's government stop its military operations in the country's southeast.
U.N. Secretary-General Ban Ki-moon also welcomed the freeing of the seven observers with the OSCE -- the Organization for Security and Cooperation in Europe. The monitors were freed Saturday, along with their five Ukrainian assistants. In a statement, Mr. Ban's spokesman said the U.N. chief expresses his appreciation to all who helped facilitate the release, including Russia.
According to news organizations, an insurgent leader said he ordered the release because of increasing insecurity in the city.
The separatists had seized the group in the flashpoint town of Slovyansk more than a week ago, claiming some members were spies.
The team had been acting under the authority of a four-party agreement directing the Vienna-based OSCE to monitor security and human rights in Ukraine's Russian-speaking east and south.
Pro-Russian gunmen have seized control of a number of key facilities in eastern Ukraine. They have declared a May 11 referendum on whether to secede from Ukraine and join Russia.
In another development Saturday, the interim government declared at least two days of mourning in the port city of Odessa where clashes Friday between pro-Russian separatists and supporters of the central government in Kyiv resulted in at least 42 deaths.
Most of the people died in a building fire that broke out during the fighting. Odessa, a key Black Sea port, had escaped most violence gripping large parts of eastern Ukraine.
U.N. chief Ban was said to be "deeply saddened by the tragic loss of lives" and called for "swift and conclusive investigations" into the incident.
In Moscow, a spokesman for Russian President Putin called a Ukrainian offensive under way in Slovyansk "a criminal act." He also said it had "effectively destroyed the last hope" for implementing an April 17 international accord aimed at defusing the crisis.
Mr. Putin on Thursday demanded that Ukraine withdraw all military personnel from the troubled region near the Russian border.
In Washington, U.S. President Barack Obama -- speaking alongside German Chancellor Angela Merkel -- said that if Russia's leadership continues to destabilize eastern Ukraine, the U.S. and European Union will move quickly to impose additional penalties, including both diplomatic and economic sanctions.