Western powers must close the road to presidency for Ukraine's leading neo-Nazi Dmytro Yarosh, the Russian Foreign Ministry's special envoy for democracy and supremacy of law,
Konstantin Dolgov has written in Twitter.
Rallies were planned across Ukraine on Sunday as the troubled ex-Soviet state struggled to contain upheaval amid a standoff between Russia and the West over Crimea that shows no sign of easing.
Russian President Vladimir Putin has seemingly been in the "deep freeze" since the Cold War and is applying its outdated KGB mentality in Ukraine, Britain's deputy prime minister said Saturday.
Ukraine braced Saturday for new pro-Russian protests in the tense eastern city of Donetsk after Moscow threatened to stop crucial gas supplies to the country, further escalating hostilities with the West.
New Ukrainian power intends to enjoy the fruits of its victory to attack human rights and freedoms, Russian Foreign Minister Sergey Lavrov said at the 25th session of the UN Human Rights Council on Monday.
Gazprom's supply contract with Ukraine may be revised, deputy chairman of the gas export monopoly's managing committee and head of the company's finance and economic department Andrey Kruglov told investors in London.
Ukraine has placed its army on full combat alert, but with ageing equipment and limited personnel, it has remained cautiously defensive in the face of an incursion by Russian forces.
US Secretary of State John Kerry bluntly warned Russia Sunday that it risked losing its seat among the prestigious Group of Eight nations, as well as economic turmoil, if it fails to pull its forces out of Crimea.
Ukraine warned Sunday it was on the brink of disaster and called up all military reservists after Russia's threat to invade its neighbour drew sharp rebukes from the United States and its Western allies.
The situation in Ukraine consolidates the Russian society, chairman of the State Duma's committee on the CIS, Eurasian integration and compatriots Leonid Slutsky says.
The United States on Wednesday warned Russia against any military intervention in Ukraine as it revealed it was drawing up an economic aid package including $1 billion in loan guarantees.
The United States and Britain on Tuesday voiced support for Ukraine amid its political turmoil, vowing it should not be seen as a battleground between East and West.
Israel's Jewish Agency has sent funds to boost security for the 200,000-strong Jewish community in Ukraine following the deadly political protests there, a spokesman said Sunday.
President Barack Obama held "constructive" talks Friday with Russian President Vladimir Putin as he pressed for swift implementation of a deal to end Ukraine's deadly crackdown on protesters.