HONOLULU (AP) — President Barack Obama and Russian President Dmitry Medvedev (dih-MEE'-tree med-VYEH'-dyev) are hailing the Senate's ratification of a nuclear arms pact between their nations as a historic event.

The two leaders spoke by phone Thursday, a day after the Senate ratified the New START treaty. The White House says Obama and Medvedev agreed to continue cooperation on a range of critical issues.

Obama made the treaty's final passage a top national security imperative during the lame-duck session of Congress that ended Wednesday. The White House said it was crucial for the U.S. to ratify the treaty in order to maintain positive relations with Russia.

Obama spoke with Medvedev from Hawaii where he is vacationing with his family.