Donald Trump says the decline of America is over seconds after he was sworn in as the 47th President of the United States.

The 78-year-old was sworn in for a historic second term as president on Monday, pledging a blitz of immediate orders on immigration and the US culture wars as he caps his extraordinary comeback.

With one hand raised in the air and the other on a Bible given to him by his mother, the 47th US president solemnly took the oath of office beneath the huge Rotunda of the US Capitol.

“The golden age of America begins now,” Trump announced before four former US presidents including immediate-past president Joe Biden.

“We will be the envy of every nation. I will very simply put America first. Our sovereignty will be claimed, and the chaos of justice will be rebalanced. America’s decline is over,” he said.

The Republican chief also said he escaped assassination to make America great again. He said America won’t forget God during his administration.