Putin says to head Russia's biggest party

President Vladimir Putin accepted an offer to become chairman of Russia's biggest party, a move that would entrench his influence after stepping down as Kremlin leader next month.

"I accept the invitation of the party. I am ready to take on myself the additional responsibility and head the party," Putin told delegates at a United Russia party conference in Moscow which was broadcast live by state television.

United Russia, which controls the Duma (lower house of parliament), created the post of chairman this week specially for Putin, who helped found the party.