He was sending the new START treaty to the Senate on Thursday, U. S. President Barack Obama told Russian President Dmitry Medvedev.

The two world leaders signed the bilateral nuclear arms reduction treaty last month in Prague, Czech Republic. The pact, which would cut the two countries' nuclear arsenals by about a third over seven years, requires ratification by the U. S. Senate and Russian lawmakers.

Obama and Medvedev during their morning phone call agreed the treaty, replacing one that expired in December, should be ratified expeditiously and in concert by both countries, an update provided by the White House said.

Russian officials later confirmed Moscow is ready to ratify the treaty simultaneously with the United States, RIA Novosti has reported. The Russian news agency also said that Russian Foreign Minister Sergei Lavrov said documents related to the pact would be submitted soon to the lower house of Parliament.

It was further reported that the presidents also discussed the two countries' common efforts to promote peace in the Middle East and reach a U. N. Security Council resolution dealing with Iran's nuclear program. (With Inputs from Agencies)