One of President Donald Trump's fiercest supporters has slammed his decision to host peace talks with Ukraine rather than focus on crises closer to home.

Steve Bannon, who served in Trump's first administration, said Trump's focus on the Russia and Ukraine war was to the detriment of Americans in crime ravaged communities.

Bannon singled out Washington D.C., which has become the center of controversy this month amid fears it is gripped by rampant crime.

'The war we got to win is right here in this country, and it's in Washington D.C.,' Bannon said.

'It's going to be in New York City. It's in Chicago, and most importantly, right now, with Gavin Newsom and all his big talk, it's in Los Angeles, California. That's the war that we got to be focused on.'