Official voter turnout in the North Caucasus was among the highest in Russian Federation, with around 92% in both Kabardino-Balkaria and Chechnya.
During his new presidential period, Vladimir Putin has promised to improve Russia's defenses against the western world, and to raise the living standards of the population.
Putin's victory in the presidential election on Sunday gives him at least another six years in power as Moscow's relations with the West become increasingly strained.
Putin's most serious contender for president, Alexei Navalny, was barred from running after being convicted of fraud.
The country said that the Russian Central Election Commission's website was hit by a coordinated distributed denial of service (DDoS) attack with IP addresses originating from 15 different countries. "Our people always unite in the trying hour".
The vote was tainted by widespread reports of ballot-box stuffing and forced voting, but the complaints will likely do little to undermine Mr Putin.
Maas said: "The result of the election in Russian Federation surprised us just as little as the circumstances of this election - we certainly can't talk in every aspect about a fair political contest as we know it".
ABC News notes that both carrots and sticks were employed to drive Russians to the polls.
At many polling stations the atmosphere was festive, with patriotic songs blasting out of speakers, cheap food available to voters and entertainers organising games for children.
Police Seize Car After Driver Shows Them Homer Simpson License
Thames Valley Police team may have seen a few fake driver's licences in their time, but none quite like this, no doubt. One person wrote: "Everyone knows that Homer Simpson lives at 742 Evergreen Terrace! ".
But employees of state and private companies, as well as students, reported coming under pressure to vote. He will be leading the country for another six years, until 2024. And Komsomolskaya Pravda, the country's best-selling tabloid, said Putin had won an enormous new electoral mandate stemming from a "colossal demand for a response to the piled-up grievances" that Russians have against the West.
"We need to say thank you to Great Britain because they again misread the Russian mindset", he said.
Navalny said his team planned to stage protests over "unprecedented violations" but released few details.
Navalny's movement and the non-governmental election monitor Golos reported ballot stuffing, repeat voting and Putin supporters being bussed into polling stations en masse.
"Unfortunately, we have to note that not all candidates behaved honestly in line with worldwide standards", said a Golos spokesman, without naming specific candidates. "This really is the ideal moment".
With 99.8 per cent of the vote counted, the Central Election Commission said Monday that communist Pavel Grudinin came a distant second with 11.9 per cent support.
Putin's successful re-election as Russian president is a right choice made by the Russian people, Xi said, adding he believed that under Putin's leadership, the Russian people will definitely continue to focus their attention and energy and forge ahead in unity to keep making new achievements in national development and revival.
The longer-term question is whether Putin will now soften his anti-Western rhetoric. "A choice without a real competition, as we have seen in this election, unfortunately is not a real choice", Michael Georg Link, one of the joint heads of the OSCE mission, told reporters in Moscow.
German Foreign Minister Heiko Maas earlier said Russian Federation would remain a "difficult partner".