The US has warned Russia of further sanctions unless it helps convince Ukrainian separatists to leave government buildings. They have so far ignored the terms of a deal to de-escalate the crisis and refused to budge.
US national security advisor Susan Rice said Moscow must use its influence to persuade pro-Russian activists to implement the Geneva deal, which order those occupying administrative buildings to disarm and leave.
Rice warned that the US was otherwise prepared to target further sanctions on "very significant sections of the Russian economy."
"We believe that Russia has considerable influence over the actions of those who have been engaged in destabilizing activities in eastern Ukraine," Rice said.
Meanwhile in a phone call with Russian Foreign Minister Sergei Lavrov, US Secretary of State John Kerry warned that the next few days were "pivotal."
Enforcing calm is a 'collective responsibility'
The Kremlin immediately hit back, accusing the US of treating Russia "like a guilty schoolboy."
"Our Western colleagues are trying to push responsibility towards our side. But it must be underlined: it is collective responsibility," Spokesman Dmitry Peskov told Russian television.
He noted that pro-Western protesters in Kyiv had also not yet ended their occupation of the iconic Maidan square, despite achieving their aim of ousting President Viktor Yanukovych earlier this year.
The latest rhetoric indicatives that the Geneva deal, agreed on Thursday by the US, Ukraine, EU and Russia, already appears to be crumbling.
Alongside the end to occupations, it also ordered the immediate dissolution of "all illegal military formations" in Ukraine and granted amnesty to all anti-government protesters.
It has been widely overlooked by pro-Russian separatists who have continued their occupation of government buildings in a number cities in Ukraine's largely Russian-speaking east.
Interim government 'must leave first'
A spokesman for the protesters has dismissed the deal as "illegal," saying protesters would not give up until the interim government stepped down.
He said: "We agree that the buildings should be vacated, but first Yatsenyuk and Turchynov (the interim prime minister and president) must leave the buildings that they are occupying illegally since their coup d'etat."
Ukraine's east, which has a large ethnic Russian population, has been plagued by violence since the Kremlin-allied president following mass pro-Western demonstrations.
The Crimean Peninsula has since joined the Russian Federation following an overwhelmingly-backed referendum and activists in the eastern Donetsk region now hope to do the same.
In a bid to calm the crisis on Friday, the Ukrainian government pledged special status for the Russian language, as well as increased autonomy for eastern regions.
However it said it would continue its anti-terrorist operation against the activists.
ccp/jm (AFP, Reuters, AP)