As investigation intensifies, Trump asks crowd if there were any Russians in it

In the wake of special counsel Robert Mueller's investigation, United States President Donald Trump attacked Democrats in his Thursday's address at the heart of Trump country, Huntington, West Virginia.

The President also offered a political argument for why the Russia story was "a total fabrication" on a day of dizzying revelations about the probe.

"Are there any Russians here?" he said.

"Most people know there were no Russians in our campaign, there never were. We didn't win because of Russia, we won because of you," Trump said at the raucous campaign rally.

"They can't beat us at the voting booths so they are trying to cheat you out of the future and the future that you want," the President told the crowd.

"I just hope that the final determination is a truly honest one which is what the millions of people who gave us our big win in November deserve and what all Americans who want a better future want and deserve," he added.

Trump's message followed a significant breaking news on Thursday over Mueller's probe into allegations of collusion between Trump campaign aides and Moscow.

Mueller had convened a grand jury in a sign that his panel is expanding and making progress. His team had seized on financial ties between Trump and associates and Russia.