MOSCOW — Russian President Vladimir Putin has submitted the nomination papers required for him to run for re-election.

Putin's visit to the Central Election Commission on Wednesday came a day after his supporters, ranging from lawmakers to athletes, signed up to endorse his candidacy.

Putin is seeking his fourth presidential term as an independent candidate. Russian law requires independents to secure endorsements from at least 500 people.

Candidates approved by the commission then can start collecting the signatures needed to appear on the ballot.

Putin's most formidable foe, opposition leader Alexei Navalny, filed his papers on Sunday. The next day, the commission refused to allow him to solicit signatures because of a criminal conviction he and his supporters consider political retribution.

Putin's approval rating is about 80 percent heating toward the March election.