By Nathan Hodge, Kara Fox and Angela Dewan, CNN

(CNN) -- Vladimir Putin is set to extend his power in Russia for another six years after winning Sunday's presidential election with a decisive 73.9% of the vote, a state-run exit poll shows.

Putin was widely expected to win his fourth term as President, with no meaningful opposition in the running and his fiercest opponent, Alexei Navalny, barred from the race.

Exit polls are not final, and official results are gradually being released. An official win of more than 73% of the vote would be a major boost to Putin, who already enjoys sweeping powers over his country. He won 63.6% of the ballots in the 2012 election, but the number of people who turned out this time was not immediately clear.

Putin declared victory in front of thousands of people gathered in below-freezing temperatures at Moscow's Manezhnaya Square near the Kremlin, calling for unity in the country.

"We are a great big team together and I am a member of your team," he said, after a colorful show of high-energy musical performances.

No candidate came close to Putin in the race. The Communist Party's Pavel Grudinin was a distant second with 11.2% of the vote, according to the exit poll conducted by the state-owned Russia Public Opinion Research Center.

Putin has dominated Russian politics for 18 years and was already the country's longest-serving leader since Soviet dictator Joseph Stalin.

His election win will take his rule to 2024, when he will be 71. But the President hasn't groomed a successor, prompting speculation he may try to find ways to extend his power beyond this term.

Uneven playing field

Putin's critics have slammed the election as unfair, citing the Kremlin's tight control over the media, quelling of the opposition and restrictions on some election monitors to ensure a free vote.

Opposition activists and the non-governmental election monitoring group Golos reported voting irregularities. By early evening Sunday, Golos had counted 2,000 incidents, including observers being prevented from carrying out monitoring.

The vote was a huge logistical undertaking, taking place across Russia's 11 time zones over 22 hours, in around 97,000 polling stations, according to the Central Election Commission.

The Kremlin had aimed for a turnout of more than 70% to cement its legitimacy, but the election period was muted and marked by a sense of voter apathy.

Alexander G. a 23-year-old model, said he abstained from voting.

"For now it's just one Putin, and other candidates are a circus -- we don't really have an option," he told CNN outside a Moscow cafe on Sunday night.

His friend, 21-year-old modeling agent Max V, also chose not to vote, saying there weren't enough candidates to choose from.

"Everyone knows that Putin will be the president again. I would have like to have had an option. I think there will be an alternative one day but many years later."

Several Russians told CNN of a culture of pressure to support the President. A public service employee who asked to remain anonymous said that all the workers in his office were verbally told to go to a celebration rally commemorating the election on Sunday evening.

"A satisfied Putin will come out and give a speech," he said.

Russia locks horns with West

There was little fanfare in the campaign period and Russian news was dominated by developments in political crises between Russia and Western powers.

Russia has been embroiled in a diplomatic crisis with the UK in the run-up to the vote over the poisoning of a Russian ex-spy, his daughter and a police officer on British soil earlier this month. British Prime Minister Theresa May said Russia was "highly likely" behind the attack, which involved a military-grade nerve agent. Russia denies the allegation, and both countries have since expelled diplomats over the row.

Relations with the United States took another hit after Washington on Thursday announced new sanctions on Russia over its reported meddling in the 2016 US presidential election. Russia has vowed retaliation.

Despite criticisms of the Kremlin's actions ahead of the election, Putin is a genuinely popular figure in Russia, and confrontation with the West has boosted his approval ratings, past polling shows.

Crimea votes

Russia's parliament, which is controlled by Putin's United Russia party, moved the vote date back to March 18 to coincide with the fourth anniversary of Russia's annexation of Crimea from Ukraine.

Sunday's election was the first presidential vote on the Crimean peninsula since Moscow annexed the territory from Ukraine in 2014, prompting a further decline in Russia's relations with the West.

But Kiev refused to allow Russians in the country to vote at consulates, according to a statement from the government information agency Ukrinform. Only Russian diplomats were allowed to access official Russian premises.

The-CNN-Wire

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