Medvedev's spokeswoman Natalya Timakova said on Thursday that when he signed the New START treaty with President Barack Obama, they agreed that the ratification process should be conducted simultaneously.
She said that Medvedev voiced hope that both houses of Russian parliament would ratify the pact, but added that they would need some time to analyse the Senate's conditions for its ratification before making their decision.
Legislators in the Kremlin-controlled parliament had said before the Senate landmark ruling on Wednesday that they would approve the treaty quickly after it was ratified in the US
Lower house speaker Boris Gryzlov, however, told reporters on Thursday that the Senate's ratification resolution contained some conditions and the legislators need to study the text carefully before making their decision.
He added that the State Duma may ratify the pact on Friday if the text of the treaty itself remained unchanged.
"If these conditions don't change the text of the treaty, we may pass a ratification bill even tomorrow," Gryzlov said.