Trump says son is "innocent" over emails about Russian campaign help

US President Donald Trump on Wednesday decried the deepening scandal – over alleged Russian efforts to secure his White House victory – that has ensnared his eldest son as a political "witch hunt".

Trump took to Twitter to defend Donald Trump Jr after the release of emails showing his namesake's embrace of a Russian offer to provide derogatory information about his 2016 presidential opponent Hillary Clinton.

"My son Donald did a good job last night," Trump said in an early morning tweet, referring to a Fox television appearance by Trump Jr in which he sought to defend his actions.

TRT World's Sally Ayhan has more on the story.

Trump, who has kept a low profile since returning over the weekend from the Group 20 summit in Germany, said his son was "open, transparent and innocent".

"This is the greatest Witch Hunt in political history. Sad!" Trump tweeted, hours before he was scheduled to leave Washington for a visit to France.

The latest revelations have put the president's son at the centre of the scandal involving multiple US investigations into whether Trump associates colluded with Moscow in a bid to tilt the election in the Republican's favour.

The Washington Post reported on Wednesday that the continuing controversy has thrust the fledgeling White House into "chaos" and left Trump "enraged that the Russia cloud still hangs over his presidency."

Since taking office in January, Trump has seen his efforts to push his conservative agenda stalled by the unending firestorm over his campaign's alleged ties with Russia.

The controversy spilt over on Wednesday into the senate confirmation hearing for Trump's nominee to lead the FBI, Christopher Wray. Wray was named after the president fired FBI director James Comey in May in frustration over the persistent Russia probe.

Under questioning, Wray said he had not discussed the investigation – now in the hands of an independent prosecutor, former FBI director Robert Mueller – with Trump, and pledged to insulate the agency from political interference.

"There is only one right way to do this job, and that is with strict independence," Wray said. "And certainly without regard to any partisan political influence."

Wray also dismissed criticism of the Mueller investigation. "I do not consider Director Mueller to be on a witch hunt," the FBI nominee said.

"I love it"

Trump Jr released emails on Tuesday in which he was told he could get "very high level and sensitive information" that was "part of Russia and its government's support for Mr Trump."

In response, the 39-year-old – who runs the family real estate business – wrote back saying, "if it's what you say, I love it."

He then met Natalia Veselnitskaya, a woman described in the emails as a "Russian government attorney."Trump's then-campaign manager Paul Manafort and his son-in-law Jared Kushner also attended the June 2016 meeting.

Speaking to Fox News, Trump Jr said he went along to see what it was about.

But he said he didn't mention the meeting to his father after it failed to yield any compromising information, describing it as "such a nothing. There was nothing to tell."

The president's lawyer, Jay Sekulow, said Trump had not been aware of his son's meeting with the Russian lawyer until "very recently" and did not know about the emails.

While Trump said he confronted President Vladimir Putin about Russian interference when they met in Hamburg for the G20, Sekulow remained equivocal about Moscow's role.

Asked if he believed US intelligence assessments that Russia interfered in the election, Sukelow told CNN, "I have no idea what Russia tried to do or didn't try to do… I have no idea if they interfered."

US intelligence agencies have concluded that Putin approved a mass effort to tilt the election in Trump's favour, including hacking and leaking embarrassing emails from Democrats.

The latest disclosures all but ensure the president's son will come under scrutiny by investigators in Congress and at the FBI who are probing whether Trump's team was in the know.

"Fiction"

Kremlin, meanwhile, insisted it had no links to the Russian lawyer, and the Russian billionaire identified as a middleman for the Donald Jr meeting also sought to distance himself.

"We have already said that we are absolutely not familiar with this whole story," Kremlin spokesman Dmitry Peskov said.

"We never had any contact with this lawyer," Peskov said. "She doesn't have even the slightest relation to us."

In the emails released Tuesday, Rob Goldstone – a publicist close to the Trumps – tells Trump Jr that Russia's general prosecutor met real estate mogul Aras Agalarov and allegedly offered to provide the Trump campaign with dirt on Clinton.

The Agalarov family has established ties to the Trumps and brought the future US leader to Moscow for the 2013 Miss Universe beauty competition.

But Agalarov rubbished the emails touting him as a go-between for the Trumps and the Kremlin and said he only vaguely knew Goldstone.

"I think this is some sort of fiction. I don't know who is making it up," Agalarov told Russia's Business FM radio station, according to a transcript posted online.