Russian cities have been rocked by demonstrations since Monday as protesters rallied against alleged election fraud during Russia's parliamentary elections, which saw Putin's United Russia Party retain control in the Duma, the lower house of parliament, but by a smaller margin. At least 1,000 people have been detained.
More than 25,000 people have indicated on social network sites they would attend a sanctioned protest in Moscow's Revolution Square Saturday, RIA Novosti reported.
"As far as acts of street democracy go ... if people act within the law, they should be given the right to express their opinion and we should not restrict anybody's civil rights," Putin said Thursday. "If anyone breaks the law, law enforcement bodies should demand they observe the law, using all legal methods."
During an interview with a Moscow radio station, opposition leader Vladimir Milov warned there could be possible violence at Saturday's rally and urged people to stay away.
Moscow city officials cautioned Solidarnost it could face charges if more than 300 people, the number sanctioned for the march, attend the protest.
"No one wants a development of the kind of situation that happened in Kyrgyzstan and Ukraine not so long ago," Putin said, referring to revolutions in the former Soviet states. "No one wants chaos."
Putin accused the United States of being behind the protests. He said comments by Secretary of State Hillary Clinton "set the tone for some opposition activists" and "gave them a signal."
The United States and international observers have criticized the elections. President Dmitry Medvedev said the allegations, which include claims of fraud and ballot-box stuffing, will be investigated.
Looking ahead to the presidential elections early next year, Putin selected filmmaker Stanislav Govorukhin to run his campaign, RIA Novosti said.
Speaking to supporters Thursday, Putin said he wants to use the All-Russia People's Front, as the basis for his campaign.
"I would like to create my [presidential campaign headquarters] at the offices of the All-Russia People's Front, an organization that is above parties, that unites all the people of the Russian Federation," the prime minister said.