US Vice President Joe Biden on Saturday called for Americans to back President Barack Obama's push to raise the federal minimum wage, intensifying debate ahead of mid-term congressional elections in November.Obama unveiled a proposal to increase the federal minimum wage from $7.25 to $10.10 (7.35 euros) an hour in his State of the Union address in January as he set about closing income disparity -- an increasingly important theme in US politics.But rival Republicans have long argued that raising the minimum wage would hurt the economy and employment because it would prompt small businesses to tighten belts and lay off some workers."There’s no reason in the world why an American working 40 hours a week has to live in poverty," Biden said in a weekly address in place of Obama, who is in Saudi Arabia."But right now a worker earning the federal minimum wage makes about $14,500 a year. And you all know that's incredibly hard for an individual to live on, let alone raise a family on."But if we raise the minimum wage to $10.10 an hour, that same worker will be making $20,200 a year -- and with existing tax credits would earn enough to bring that family or a family of four out of poverty."Not only would it put more hard-earned money into the pockets of 28 million Americans, moving millions of them out of poverty, it’s also good for business."In January, Obama urged Congress to raise the federal minimum wage. A congressional watchdog says that it could lift 900,000 people above the poverty line but may cost half a million jobs.