Donald Trump has defended his eldest son amid a row over his meeting with a Russian lawyer during the presidential campaign.

The President tweeted to say Donald Trump Jr had been "open, transparent and innocent" during an interview with Fox News, and hit out at what he called the "greatest witch hunt in political history".

But the man picked by the US President to lead the FBI denied an investigation into possible co-ordination between Russia and his campaign is a "witch hunt".

Mr Trump Jr spoke to Russian Natalia Veselnitskaya in June 2016 in the hope of unearthing compromising information on his father's then Democratic rival Hillary Clinton.

Speaking to Fox, he insisted he did not tell his tycoon father about the meeting, and claimed his discussion with her was "literally just a wasted 20 minutes".


Trump Jr: Father did not know about Russia meeting

The President has now tweeted: "My son Donald did a good job last night. He was open, transparent and innocent. This is the greatest Witch Hunt in political history. Sad!"

He added: "Remember, when you hear the words "sources say" from the Fake Media, often times those sources are made up and do not exist."

:: Trump Jr claims a 'gear change' in Russia scandal

Image: Donald Trump has hit out at a 'witch hunt' during tweets

When asked by presenter Sean Hannity whether he had briefed his father, Mr Trump Jr said: "No. It was just a nothing. There was nothing to tell."

However, the 39-year-old conceded: "In retrospect, I probably would have done things a little differently.

"For me this was opposition research, they had something, you know, maybe concrete evidence to all the stories I'd been hearing about. So I think I wanted to hear it out. But it really went nowhere."

Trump Jr: Russia meeting was 'waste of time'

On Wednesday Christopher Wray, the former high-ranking Justice Department official who is Mr Trump's pick to head the FBI, denied the investigation into Russia collusion was a "witch hunt".

He told senators at his confirmation hearing the bureau's work will be driven only by "the facts, the law and the impartial pursuit of justice".

Speaking about Robert Mueller, the former FBI director selected in May as the special counsel to oversee the investigation, he said: "I do not consider Director Mueller to be on a witch hunt."

Image: Mr Trump Jr explains on Twitter he published the emails 'to be totally transparent' Image: Mr Trump Jr is told Russia's crown prosecutor is the source of the information Image: 'If it's what you say I love it,' the President's son says Image: Publicist Rob Goldstone and Mr Trump Jr attempt to organise a phone call Image: Mr Trump Jr asks to be called on his mobile phone Image: Mr Trump Jr is told he will be meeting 'the Russian government attorney' Image: The President's son says he will be joined by Jared Kushner, Ivanka Trump's husband Image: Mr Trump Jr says he will 'lock' the meeting with the Russian lawyer Image: Mr Kushner and Trump campaign manager Paul Manafort are sent confirmation of the meeting /

Mr Trump Jr's meeting was arranged after he received an offer of "very high level and sensitive information" about Mrs Clinton.

In emails released by Mr Trump Jr himself, the intermediary, publicist Rob Goldstone, describes the offer of information as "part of Russia and its government's support for Mr Trump".

After screenshots of the communication were uploaded on Twitter, the President lauded his son as a "high-quality person" and praised his "transparency".

The White House has branded talk of perjury and treason over alleged links to Moscow as "ridiculous", adding the President is "frustrated" that Russia continues to be an issue and would love to move on.

:: Trump Jr emails are 'tip of the iceberg'

Trump Jr emails show Russia communication

During his Fox News interview, Mr Trump Jr appeared to suggest it was a "shame" that the meeting with Veselnitskaya amounted to nothing.

The talks had also been attended by the President's son-in-law Jared Kushner and Paul Manafort, the Trump campaign chief at the time.

The Senate Judiciary Committee on Wednesday summoned Mr Manafort to appear before the panel.

Republican Senator Chuck Grassley said he has several questions for Mr Manafort and would issue a subpoena to force him to appear if necessary.

Alleged links between the Trump campaign and Russia - along with Moscow's possible meddling in the US election - are currently the focus of a number of inquiries, including a probe by special counsel Robert Mueller, a former FBI chief.

Democratic Senator Ron Wyden said the emails show the Trump campaign "sought to collude with a hostile foreign power to subvert America's democracy", although Republicans have played down the revelations.

Chuck Schumer, the Democratic leader in the Senate, called on Mr Trump Jr to hand over all documents related to contact with Russia.

Mr Trump Jr is also facing calls to appear before a congressional committee.