Barack Obama says: ‘Best is yet to come’

Earlier, Mitch McConnell, the Republican leader in the Senate, said voters had not endorsed “the failures or excesses of the president’s first term”.

“They have simply given him more time to finish the job they asked him to do together with a Congress that restored balance to Washington after two years of one-party control,” McConnell added.

Mr Obama will also have to contend with Mr Romney’s running mate, Paul Ryan, who has confirmed he will remain in Congress as the Republican’s budget chairman.

The president faces his first challenge when Congress returns next week to begin dealing with the fiscal cliff.

Economists warn that the measure – set to be triggered in January unless lawmakers can find agreement – could plunge the nation back into a recession.

Mr Obama was re-elected with the highest unemployment rate – at 7.9% – for any incumbent president since the US wartime leader Franklin Roosevelt.

The fragile economy was rated the top issue by about six out of 10 voters in Tuesday’s exit polls. But most of them blamed former President George W Bush for the downturn.