Obama calls ratifying START treaty US imperative

US President Barack Obama sternly proclaimed ratification of the US-Russia nuclear arms treaty "a national security imperative" Thursday, saying the Senate must act before Congress goes home for the year.

Lobbying hard for votes from the White House, Obama he expressed confidence he would be able to get enough votes to get the treaty passed, saying that every president since Ronald Reagan has been able to get such pacts through. (AP)