Trump slams Russia probe as 'fake story' after grand jury assembled

Donald Trump has slammed the investigation into alleged Russian meddling in the presidential election as a "fake story", as news broke that a grand jury has been convened to examine evidence.

The move by Special Counsel Robert Mueller is seen as an intensifying of the probe into potential links from the Kremlin to Donald Trump's campaign.

Speaking at a campaign rally in Huntington, West Virginia, the US President challenged Democrats to either continue their "obsession with a hoax" or begin serving the interests of the American people.

Speaking just hours after it emerged that a grand jury had been assembled, he told the crowd: "The Russia story is a total fabrication. It's just an excuse for the greatest loss in the history of American politics - it just makes them feel better when they have nothing else to talk about."

A grand jury is a standard prosecution tool in criminal investigations, suggests that Mr Mueller and his team of investigators are likely to hear from witnesses and demand documents in the coming weeks and months.

Grand juries are common vehicles to order witnesses and records to present evidence in court.

However, the appointment of a grand jury does not suggest any criminal charges are near or will necessarily be sought.

Washington defence lawyer Jacob Frenkel described the move as simply "logical next step in this investigation", given that it is the traditional method for prosecutors to gather evidence.

"The use of the grand jury neither escalates, nor establishes a timeline for, the investigation," he said.

However, Trump has branded the investigation into alleged Russian meddling a "witch hunt" and denied his campaign team formed connections with Moscow during the 2016 campaign.

The Wall Street Journal reported ex-FBI chief Mr Mueller began secret hearings two weeks ago.

The hearings are understood to be looking at evidence related to the meeting the US president's son Donald Trump Jr and son-in-law Jared Kushner - now his White House senior adviser - held with a Russian lawyer that promised to provide material to smear his rival Hillary Clinton.

It is not known if the Washington grand jury is connected to the work of a separate one in Alexandria, Virginia, which has been used to gather information on Michael Flynn, Donald Trump's former national security adviser.

Both men have denied colluding with representatives of the Russian government while White House lawyers said they do not believe the president is under investigation.

Jared Kushner has denied colluding with the Kremlin. Credit: AP

At the Huntington campaign rally, Mr Trump branded the investigation a "fake story that is demeaning to all of us and most of all demeaning to our country and demeaning to our constitution".

"I just hope 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," Mr Trump told the crowd.

He continued: "We didn't win because of Russia. We won because of you."

Mr Trump argued that Democrats are pushing the "totally made-up Russia story" because "they have no message, no agenda and no vision".

And he told Democrats: "Try winning at the voter booth. Not going to be easy, but that's the way you're supposed to do it."

Trump supporters at the rally got a further boost on Thursday evening when West Virginia Governor, Jim Justice, announced that he is deserting the Democrats and joining the Republicans.

"This man is a good man. He's got a backbone. He's got real ideas," Mr Justice said about the president.

"He cares about America. He cares about us in West Virginia."

Mr Trump overwhelmingly won West Virginia, partly due to his promises to revive a slumping coal industry. Credit: AP

Mr Trump has been increasingly infuriated by the depth of Mr Mueller's investigation, but lawyers for the US President earlier said they were unaware of the existence of a grand jury and had no information to suggest the billionaire businessman was under federal investigation.

"With respect to the news of the federal grand jury, I have no reason to believe that the President is under investigation," defence lawyer John Dowd said.

Ty Cobb, special counsel to the president, said he was not aware Mr Mueller had started using a new grand jury.

"Grand jury matters are typically secret," Mr Cobb said.

"The White House favours anything that accelerates the conclusion of his work fairly ... The White House is committed to fully co-operating with Mr. Mueller."

Mr Mueller was appointed special counsel in May by the justice department following the firing by Mr Trump of FBI director James Comey.

He has since assembled a team of more than a dozen investigators, including current and former justice department prosecutors with experience in international bribery, organised crime and financial fraud.

News of the grand jury came as senators introduced two bipartisan bills aimed at protecting Mr Mueller from being fired by Mr Trump, with both parties signalling resistance to any White House effort to derail the investigation into Russian meddling in last year's election.

Donald Trump has bemoaned his nation's worsening relations with Russia. Credit: AP

The development in the investigation comes as Mr Trump was forced to sign Congress-approved Russian sanctions aimed at punishing Moscow.

The US president said his country's relationship with Russia was at an "all-time" and "very dangerous" low.

He tweeted his comments on Thursday, as Russia warned the sanctions amounted to a full-scale trade war.

The sanctions were brought for allegedly interfering in the 2016 presidential election and for its military aggression in Ukraine and Syria, where the Kremlin has backed President Bashar Assad.