The remarks by Sergei Glaziev could provoke a backlash in Ukraine and fuel tensions between Russia and the west, which have accused each other of interference in a cold-war type geopolitical stand-off.
Mr Yanukovich “is now in a situation of creeping revolution, and to some extent he functions as the guarantee of the constitution, security and integrity of Ukraine, therefore the president has no choice,” Mr Glaziev said in an interview with the corporate magazine of Russian state gas company, Gazprom, published on the editor’s blog on Friday.
“Either he protects Ukrainian statehood and suppresses the insurgency, which is provoked and financed by external forces, or he risks losing power, and then Ukraine faces growing chaos and internal conflict from which no exit is visible.”
The comments, the first public call by a Russian official for Ukraine’s embattled president to crush the anti-government protests, which have been going on for more than two months, comes days after Mr Putin put on hold a $15bn bailout for Ukraine’s ailing economy, until a new government is formed in Kiev following the resignation of Moscow-friendly prime minister Mykola Azarov.
Moscow has so far been careful to stress that it is not interfering in the domestic political process in Ukraine, and has rejected the notion that it is fighting to retain its influence over a country Russia traditionally struggles to see as an independent nation.
But Mr Glaziev’s remarks reveal a sharp sense of bitter competition with the west over Ukraine.
He praised Moscow’s rescue package and said it had helped Kiev to avoid “catastrophe”.
He also attacked the west for allegedly nurturing aggressive russophobia in Ukraine through the support of non-governmental groups with an anti-Russian agenda.
Mr Glaziev did not immediately respond to requests for verification of the comments published in the Gazprom journal.
At the same time as Russia was urging Ukraine to take tougher action against the protests, US secretary of state John Kerry said that the concessions offered this week by the Ukrainian government were not enough to resolve the crisis.
Mr Kerry said he would seek to persuade Moscow that a political compromise in Ukraine was in its interests, however his comments underlined the starkly different ways that the US and Russia view the crisis.
“The offers of President Yanukovich have not yet reached an adequate level of reform and an adequate level of sharing so that the opposition can feel that it can legitimately come to the table,” Mr Kerry said during a visit to Berlin.
“Further violence that goes out of control is not in anybody’s interest,” he said, but Mr Kerry also urged the opposition to engage with the government if it was offered reforms that included “genuine participation”.
His remarks follow a warning by Arseniy Yatseniuk, one of Ukraine’s opposition leaders, of an imminent crackdown on anti-government protesters camped in seized buildings and a barricaded tent city in central Kiev.
On Thursday, Mr Yatseniuk pleaded for the west to intervene with an “enormous effort” to stabilise Ukraine.
He said: “What we know for sure is that a so-called counter-terrorism operation is being prepared to be launched by the security forces and riot police.”
Family members of some senior law enforcement officials have already left the country, Mr Yatseniuk added.