"Mr. Trump, he has probably chosen his own method to get through to voters' hearts," Putin told foreign policy experts in southern Russia.

"He behaves extravagantly of course, we see this, but I think there's a reason for this, because in my opinion he represents the interests of that part of society - and it is quite big in the United States - which is tired of the elite who have been in power for decades."

Putin also said that cyber attacks or other types of interference in other countries' internal affairs were intolerable.

The U.S. government has formally accused Russia of a campaign of cyber attacks against Democratic Party organisations in the run-up to the U.S. presidential election.

Russian officials have denied those allegations.