Moscow, April 27 (IANS/RIA Novosti) Outgoing Russian President Dmitry Medvedev Friday accepted a formal offer to take up the leadership of the ruling United Russia party, two days after Prime Minister Vladimir Putin resigned from the post.

Medvedev said he would "join the party's ranks", something Putin, who has led it since its inception in the early 2000s, had never done.

In a meeting Friday with top party officials in his Gorky residence outside Moscow, Medvedev said a president should be a "party member".

"Otherwise we will not be able to explain to the people which political force is in power," he said.

Medvedev stands down in May after four years in office and is expected to be given the post of prime minister as part of a power swap agreed with Putin last year.

United Russia has suffered a significant fall in its popularity, according to opinion polls after the disputed parliamentary elections in December which critics claimed were rigged in its favour.

The Kremlin has denied the allegations, but both Medvedev and Putin, whose landslide March 4 presidential election victory was likewise marred by claims of fraud, have pledged to "renovate" the party.

--IANS/RIA Novosti

pm/dg