The national security adviser to President Donald Trump, Michael Flynn has resigned amid controversy about his contacts with Russia.

The White House confirmed that Flynn has resigned following calls for him to be sacked over his alleged contact with the Russian ambassador before Trump took over as President.

It is illegal to conduct US diplomacy as a private citizen.

Flynn in his resignation said: ‘I inadvertently briefed the Vice President Elect and others with incomplete information regarding my phone calls with the Russian Ambassador. ‘I have sincerely apologised to the President and the Vice President, and they have accepted my apology.’

The White House confirmed that Lt Gen Joseph Keith Kellogg had been appointed to replace Flynn in the interim.