The White House has confirmed that President Donald Trump helped author a discredited statement his son gave in defence of talks with a Russian lawyer during the 2016 election campaign.

In the July statement, Donald Trump Jr said he met Russian lawyer Natalia Veselnitskaya in June 2016 to discuss the adoption of Russian children.

Mr Trump Jr later admitted he had agreed to the meeting after being told he could receive damaging material on Mr Trump’s election opponent Hillary Clinton.

The Washington Post claimed in an exclusive report Tuesday that President Trump personally dictated his son’s statement while on his way back from the G20 meeting in Hamburg Germany.

“Flying home from Germany on July 8 aboard Air Force One, Trump personally dictated a statement in which Trump Jr. said that he and the Russian lawyer had ‘primarily discussed a program about the adoption of Russian children’ when they met in June 2016, according to multiple people with knowledge of the deliberations,” the Washington Post  reported Tuesday.

“The statement, issued to The New York Times as it prepared an article, emphasised that the subject of the meeting was ‘not a campaign issue at the time’.”

While denying President Trump dictated his son’s initial statement, the White House admitted he “weighed in on its content”.

“He certainly didn’t dictate (the statement),” White House press secretary Sarah Huckabee Sanders told a media briefing Wednesday morning (AEST).

“The President weighed in as any father would, based on the limited information that he had,” Ms Sanders said.

“The statement that was issued was true and there were no inaccuracies in the statement,” she said.

The NYT reported in early July that Mr Trump Jr met Ms Veselnitskaya along with Jared Kushner, the President’s son-in-law and senior adviser, and Paul Manafort, who was campaign chair at the time, in Trump Tower in June 2016.

Trump Jr’s initial statement to the NYT claimed the meeting was “primarily” about adoption and its relation to US sanctions on Russia under the Magnitsky Act.

Shortly after that first report, it was shown the initial statement was misleading when the NYT  obtained an email chain showing an acquaintance, music promoter Rob Goldstone, offered Mr Trump Jr a meeting where he could obtain information as part of a Russian government effort to help his father’s campaign.

Mr Trump Jr then posted the emails online.

The US Senate, House of Representatives and a special counsel are all investigating alleged Russian interference in the presidential election in the form of attempts to undermine Mrs Clinton.

President Trump and Moscow have consistently maintained there was not collusion to meddle in the election outcome.

The President last month launched an angry defence of his son’s meeting and his explanation.

“The Democrats want to continue to use this as a PR stunt and are doing everything they can to keep this story alive and in the papers every single day,” Ms Sanders said Wednesday.

“The President, the American people, they voted America first, not Russia first, and that’s the focus of our administration.”

– With agencies