U.S. President Barack Obama says the U.S. and Europe must act together in levying sanctions against Russia over its actions in Ukraine that he says threaten that country's independence and sovereignty.
The president, speaking Sunday in Malaysia, said the U.S. and Europe must act collectively, showing Russia the world is united in initiating sanctions.
Obama said a deal had been reached with Russia to de-escalate the crisis, but "Russia has not lifted a finger to help."
Washington and Brussels are expected, possibly as early as Monday, to name new people and firms close to Russian President Vladimir Putin who will be hit by punitive measures, but there is no consensus yet on wider economic sanctions.
On Saturday, U.S. Secretary of State John Kerry called for Russian support "without preconditions" for efforts to free European monitors seized Friday by pro-Russian gunmen in eastern Ukraine.
A senior State Department official said Kerry delivered his demand in a telephone call to Russian counterpart Sergei Lavrov. Moscow later said it is taking what it called "all measures to resolve the situation," but blamed Ukrainian authorities for failing to secure the safety of the team.
Near the eastern city of Slovyansk, separatists on Friday seized a bus carrying more than a dozen people from the Vienna-based Organization for Security and Cooperation in Europe .
The German-led monitoring team was acting under the authority of a four-party agreement directing the OSCE to monitor security and human rights in Ukraine's Russian-speaking east and south. The deal, reached in Geneva, was signed by Russia, Ukraine, the United States and the European Union.
Separately, interim Ukrainian Prime Minister Arseniy Yatsenyuk told reporters Saturday that Russian aircraft had violated Ukrainian airspace seven times overnight.
For its part, the Russian Defense Ministry said its "objective monitoring of the air situation" had not detected any overflight violations.
Meanwhile, in the eastern Ukrainian city of Donetsk, VOA correspondent Brian Padden says he was confronted by an angry mob Saturday as he tried to cover a rally in front of an occupied building. He says protesters accused him of supporting a "fascist" U.S. government.
Armed pro-Russian gunmen have seized government facilities in about 10 cities in eastern and southern Ukraine, and are demanding a referendum on whether to secede from the country and join Russia.
In a joint statement late Friday, the Group of Seven major economies announced it had agreed to "move swiftly" on new sanctions against Russia because of its alleged interference in Ukraine.
The G-7 nations said they would take measures to intensify "targeted sanctions" against Moscow. A U.S. official said the penalties could take effect as early as Monday.
Some information for this report provided by AP, AFP and Reuters.