New York: US President Donald Trump has hit out at Democrats in Congress for launching a blizzard of investigations into his administration and business dealings, saying his political opponents had gone "nuts" and were pursuing a strategy of “presidential harassment”.

House Speaker Nancy Pelosi has accused the President of delivering an “all-out threat” to legislators who are obliged to provide a check and balance on his power.

In his State of the Union address, delivered on Tuesday local time, Trump said: "An economic miracle is taking place and the only thing that can stop it are foolish wars, politics or ridiculous partisan investigations.

"If there is going to be peace and legislation, there cannot be war and investigation."