Russia's presidential election has failed to meet democratic standards, European election observers say.
Putin vowed to safeguard "democratic achievements"
Sunday's poll did not meet criteria "necessary for a healthy democratic election process", said chief observer Julian Peel Yates in Moscow.
Observers from the Organisation for Security and Co-operation in Europe (OSCE) and the Council of Europe took part in the mission.
President Vladimir Putin won more than 70% of the votes cast.
After his victory, he vowed to proceed with economic reforms and said he would safeguard democracy.
RUSSIA VOTES FOR PUTIN
1 Vladimir Putin: 71.2%
2 Nikolai Kharitonov: 13.7%
3 Sergei Glazyev: 4.1%
4 Irina Khakamada: 3.9%
5 Against all: 3.5%
6 Oleg Malyshkin: 2%
7 Sergei Mironov: 0.8%
Central Election Committee figures (99% of votes counted)
He also dismissed criticism from US Secretary of State Colin Powell, who had suggested that Mr Putin's rivals had been denied media access.
Mr Putin's nearest rival, Communist candidate Nikolai Kharitonov, came only a distant second with 13.7%.
None of the other four contenders managed to poll even 5% of the vote. The only liberal candidate, economist Irina Khakamada, finished in fourth place with 3.9%.
Mr Putin's rival candidates have complained during the campaign about their lack of access to state media.
'Essential elements missing'
At a news conference in Moscow, Mr Yates criticised the role of state-controlled media in the
run-up to the election.
Voting has been recorded in 95,000 polling stations in 11 time zones
"Essential elements...such as vibrant political discourse and meaningful pluralism were lacking," he said.
The OSCE had also criticised December's election to Russia's lower house of parliament - the Duma - as unfair and biased towards Putin's allies.
At the same time, Mr Yates acknowledged that Sunday's election was well administered.
'We shall not stop'
Mr Putin, speaking to reporters shortly after polls closed, said all "democratic achievements" would be guaranteed.
"And we shall not stop with what has been achieved. We shall strengthen the multi-party system," he said.
Mr Putin also firmly brushed aside Mr Powell's criticism as "dictated by the domestic political balance" with upcoming US elections.
"In many so-called developed democracies there are also many problems with their own democratic and voting procedures," he said, referring to the controversial George W Bush's victory over Al Gore in the 2000 poll.
The image of Mr Putin as a 21st-Century tsar evidently appealed to a people whose country has historically been ruled by a firm fist from the centre, the BBC's Stephen Dalziel in Moscow says.
But he adds that the lives of many Russians are still being blighted by the worst elements of the Soviet past which Mr Putin will need to address during his second term in office.
Russia's election officials said 64.3% of the registered voters cast ballots.
Sunday's poll was the third presidential election since the collapse of the Soviet Union in 1991.
About 95,000 polling stations across 11 time zones from the far east to Kaliningrad on the Baltic sea recorded the ballots of 109m registered voters.
Russian voters had been offered incentives to cast their ballots, from vouchers for free haircuts for pensioners to cinema tickets for young people, Reuters news agency reported.