US President Donald Trump has acknowledged that a 2016 meeting between a Kremlin-connected lawyer and his son was to collect information about his political opponent, casting new light on a moment central to the special counsel’s Russia probe.

Mr Trump, in a series of searing tweets sent from his New Jersey golf club on Sunday night (AEST), tore into two of his favourite targets, the news media and Robert Mueller’s ongoing investigation into possible links between the Trump campaign and Russia.

The President unleashed particular fury at reports that he was anxious about the Trump Tower meeting attended by his son Donald Trump Jnr and other senior campaign officials.

Attacking “Fake News reporting” he defended the meeting his “wonderful son, Donald” had in Trump Tower.

“This was a meeting to get information on an opponent, totally legal,” he said.

Fake News reporting, a complete fabrication, that I am concerned about the meeting my wonderful son, Donald, had in Trump Tower. This was a meeting to get information on an opponent, totally legal and done all the time in politics – and it went nowhere. I did not know about it!

— Donald J. Trump (@realDonaldTrump) August 5, 2018

But 13 months ago, Mr Trump gave a far different explanation for the meeting.

A July 2017 statement dictated by the President read: “We primarily discussed a program about the adoption of Russian children that was active and popular with American families years ago.”

Since then, the story about the meeting has changed several times, eventually forced by the discovery of emails between the President’s eldest son and an intermediary from the Russian government offering damaging information about Mr Trump’s opponent, Hillary Clinton.

Betraying no surprise or misgivings about the offer from a hostile foreign power, Mr Trump Jnr replied: “If it’s what you say, I love it, especially later in the summer.”

Sunday’s tweet was Mr Trump’s clearest statement yet on the purpose of the meeting. It has become a focal point of Mr Mueller’s investigation even as the President and his lawyers try to downplay its significance and pummel the probe with attacks, including labelling it a one-side “witch hunt”.

But as Mr Trump and his allies have tried to discredit the probe, a new talking point has emerged: that even if that meeting was held to collect damaging information, none was provided and “collusion” – Mr Trump’s go-to description of what Mr Mueller is investigating – never occurred.

“The question is what law, statute or rule or regulation has been violated, and nobody has pointed to one,” Jay Sekulow, one of Mr Trump’s laywers, told US broadcaster ABC.

Legal experts have pointed out several possible criminal charges, including conspiracy against the US and aiding and abetting a conspiracy.

Despite Mr Trump’s public Twitter denial, the President has expressed worry that his son might face legal exposure even as he believes he did nothing wrong, according to three people close to the White House familiar with the President’s thinking but not authorised to speak publicly about private conversations.

Mr Sekulow acknowledged the public explanation for the meeting has changed, but insisted that the White House had been very clear with the special counsel’s office.

He said he was not aware of Mr Trump Jnr facing any legal exposure.

-Reuters