During a phone call on Friday, Biden urged both Ukraine and Russia to avoid escalating tensions over Crimea.
"Yesterday's phone conversations between Biden and Poroshenko, as well as between [EU foreign policy chief Federica] Mogherini and [Ukrainian Foreign Minister Pavlo] Klimkin are signs – even unclear ones – that Western countries are damped by Kiev’s latest undertakings and are not ready to support the Ukrainian authorities as unconditionally as previously," Kosachev wrote on his Facebook page.
He said that the US calls on all parties to the conflict to deescalate tensions are a positive shift from the previous stance that Russia is the only party responsible for escalation.
"These talks for the first time in a long period do not look like a reckless and demonstrative anti-Russian solidarity," Kosachev said.
On Wednesday, Russia's Federal Security Service (FSB) said that it had dismantled a spy ring organized by the Ukrainian Defense Ministry in Crimea, which was preparing acts of sabotage on "critical and life-supporting elements of the peninsula's infrastructure."