MOSCOW — The sudden collapse of the Kremlin-backed government in Ukraine has for now delivered a profound setback to President Vladimir V. Putin’s strategy to deepen political and economic ties with the country and thus keep it from embracing Europe.
Even as Russia celebrates the closing of Olympic Games that defied some dire expectations, Mr. Putin now faces the task of reasserting Russia’s influence in a country that it considers a fraternal ally, one with deep cultural, social and political connections that bind it to Moscow’s orbit regardless of its new government.
Russia still has enormous leverage and close allies in Ukraine, particularly in the east and on the Crimea Peninsula, home of Russia’s Black Sea Fleet and a sizable ethnic Russian population that views the leaders of the political uprising that toppled President Viktor F. Yanukovych with disdain.
That has raised fears that Russia would use the disenchanted populations there as a pretext to intervene to reverse Ukraine’s new trajectory — even militarily, as the Kremlin did in two ethnic enclaves in 2008 in another former Soviet republic, Georgia.
The fears have been so palpable — and the subject of endless speculation in Ukraine and here in Russia — that President Obama’s national security adviser, Susan E. Rice, warned in a television interview on Sunday that it “would be a grave mistake” for Russia to use force. “It’s in nobody’s interest to see violence return and the situation escalate,” Ms. Rice said on NBC’s “Meet the Press.”
How exactly Russia responds remains to be seen, but the turmoil is certain to further strain relations with Europe and the United States, which officials here have denounced for meddling in Ukraine at the expense of Russia’s vital interests. At the same time, the United States and Europe have accused Russia of trying to impose its will there.
Mr. Putin’s envoy refused to sign the agreement mediated on Friday by three European foreign ministers to end two days of carnage in the capital, Kiev, only to have the agreement overtaken by a political upheaval that threatens to undercut Russia’s influence over any new government.
The Kremlin’s spokesman, Dmitri S. Peskov, complained on Sunday that while Mr. Yanukovych had honored the terms of the agreement — which called for new elections and a return of constitutional powers to the Parliament — his political opponents had not. Instead, the Parliament has effectively seized power and is now rushing through an emboldened series of votes that have provoked rage among Russian lawmakers and commentators.
“It’s a confusing situation,” Mr. Peskov said in a telephone interview from Sochi, where Mr. Putin attended the closing ceremony of the Olympic Games. “We have to figure out what we are facing there. Is it a coup or what?”
Mr. Putin has not yet made any public statements about the latest events, as is often the case when he is confronted by unexpected challenges or crises. “Let’s wait and see,” Mr. Peskov said.
Mr. Putin and Mr. Yanukovych have spoken several times in recent weeks to discuss the situation there, but Mr. Peskov said he did not know whether they had spoken since Saturday, when Mr. Yanukovych’s legitimacy evaporated and he fled Kiev, leaving protesters swarming through his opulent presidential compound.
It is clear that Mr. Putin has followed the crisis intently, even as he attended to the Olympic festivities that he clearly has relished as a symbol of a new Russia. On Friday he met with his national security advisers on Friday and a day later dispatched two Russian lawmakers to a regional party congress in Eastern Ukraine that had been called to rally opposition to the new political authorities in Kiev.
Vladimir Lukin, the envoy Mr. Putin sent to Kiev at Mr. Yanukovych’s request during the negotiations with the Europeans, returned to Moscow and criticized the European foreign ministers for siding with “the nationalist-revolutionary terrorist Maidan,” referring to the square that has been the nucleus of the protests, and not the “legitimate government that they recognized.”
Only hours before the closing ceremony in Sochi, Mr. Putin spoke by telephone with Chancellor Angela Merkel of Germany. The Kremlin said in a statement only that they discussed the situation in Ukraine, Germany’s foreign office went further, saying that the two leaders agreed that “the territorial integrity of Ukraine must be preserved.”
Russia’s foreign minister, Sergey V. Lavrov, spoke with Secretary of State John Kerry for a second time in two days, and Russia later announced that it had recalled its ambassador in Kiev because of “the deteriorating situation” in the country. The State Department released a statement saying that Mr. Kerry expressed support for the votes in Ukraine’s Parliament and called on Russia to support the transition now underway.
As in Ukraine itself, there were already some signs that Russia had given up on Mr. Yanukovych, but that hardly meant that officials in Moscow would welcome the new government that emerges. Russia’s Foreign Ministry posted a photograph on Twitter of a World War II memorial being toppled in the western Ukrainian city of Lviv, joining the many Lenin statues that have been pulled down. “Nazis comeback,” it said in muddled English.
A vote by Ukraine’s Parliament to curtail the Russian language’s role in its school curriculum, one of a flurry of new laws adopted, also prompted a similarly ominous warning from one of Russia’s deputy prime ministers, Dmitri O. Rogozin. “The main enemy — the Russian language,” he wrote on Twitter. “Then — all Russians in Ukraine. Then — all who are for a union with Russia.”
Others sounded more tempered. Russia has suspended the $15 billion in financial assistance it pledged to Ukraine in December, but its finance minister, Anton Siluanov, said Sunday that it was still possible to continue with the loans once a new government was formed. He also said Russia would abide by its current contracts to provide natural gas, something it has previously used as a lever when relations soured.
In the end, of all the problems that threatened to overshadow the Olympic Games in Sochi — terrorism, construction delays, even the weather — the one that materialized in Ukraine was one few expected.
Sergei A. Markov, a political strategist who advises the Kremlin, criticized what he called the “cynical geopolitical games” that European leaders have played in Ukraine, but also suggested that Russia, too, needed a new approach now. “It’s simply necessary for Moscow to reformat the Ukraine element of its foreign policy,” he told Interfax.
Patrick Reevell contributed reporting.