President Donald Trump stepped up his attacks on federal Special Counsel Robert Mueller's probe into Russia and the 2016 US election, saying that his campaign did not collude with Moscow but that collusion is not a crime anyway.
He launched his new attack hours before his former campaign chairman, Paul Manafort, was due to go on trial on tax and bank fraud charges in Virginia.
As the first trial in the 14-month Russia probe, the case throws a fresh spotlight on an investigation that has dogged Mr Trump's presidency.
Mr Mueller is investigating whether Trump campaign officials worked with Moscow to try to sway the 2016 US presidential election.
"Collusion is not a crime, but that doesn't matter because there was No Collusion (except by Crooked Hillary and the Democrats)!" Mr Trump wrote on Twitter.
While collusion is not a technical legal charge, Mr Mueller is probing any coordination between the Russian government and the Trump campaign, and could bring conspiracy charges if he finds that any campaign member worked with Russia to break US law.
Mr Trump has denied any collusion for months.
Collusion is not a crime, but that doesn’t matter because there was No Collusion (except by Crooked Hillary and the Democrats)!— Donald J. Trump (@realDonaldTrump) July 31, 2018
He echoed his personal lawyer, Rudy Giuliani, who said in television interviews yesterday that collusion is not a crime.
The strategy may be the latest in Mr Trump's efforts to strip legitimacy from the Mueller probe, which he has long denounced as a "witch hunt."
Legal experts said that working with a foreign national with the intent of influencing a US election could violate multiple laws.
A campaign finance law makes it a crime to solicit a "contribution or donation of money or other thing of value" from a foreign national in connection with an election, which could include opposition research.
"Collusion is basically a partnership in crime, which is conspiracy," said Randall Eliason, a former federal prosecutor and a law professor at George Washington University.
Mr Trump has denied that the campaign worked with Russia to try to engineer his victory against Democratic candidate Hillary Clinton and bristles at the suggestion he might owe his White House victory to Moscow.
The Fake News Media is going CRAZY! They are totally unhinged and in many ways, after witnessing first hand the damage they do to so many innocent and decent people, I enjoy watching. In 7 years, when I am no longer in office, their ratings will dry up and they will be gone!— Donald J. Trump (@realDonaldTrump) July 31, 2018
Russia has denied the finding of US intelligence agencies last year that it interfered to sway the election to Mr Trump.
"As a matter of law, the central question is not whether members of the Trump campaign coordinated or colluded with Russia, but whether they conspired with Russians to break a criminal statute or they broke the law themselves," the Council of Foreign Relations wrote in a background paper.
That could include hacking into Democratic Party computers, it said. "'Collusion' and 'coordination' are not legally relevant terms, but they are often used as shorthand to refer to such a criminal conspiracy," it said.