Donald Trump issued a call for unity as he warned that the "politics of revenge" and "ridiculous partisan investigations" threatened to derail the "economic miracle" taking place in the United States.

The US president, delivering his second annual State of the Union address to a joint session of Congress, appealed to Democrats to reach a compromise on paying for his proposed wall on the Mexico border, toning down his rhetoric on illegal immigration.

Mr Trump said: "We must choose between greatness or gridlock, results or resistance, vision or vengeance, incredible progress or pointless destruction. Tonight, I ask you to choose greatness.

"Victory is not winning for our party. Victory is winning for our country. Embrace the boundless potential of cooperation, compromise and the common good."

He added: "An economic miracle is taking place in the United States 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."