President Donald Trump has submitted written answers to questions from Special Counsel Robert Mueller in his probe of Russian meddling in the 2016 election.

Mr Trump’s lawyer, Rudy Giuliani, said in a statement on Wednesday morning (Australian time) that “much of what has been asked raised serious constitutional issues and was beyond the scope of a legitimate inquiry”.

Mr Giuliani added that the President provided “unprecedented cooperation” and that it was time to “bring this inquiry to a conclusion”.

A spokesman for Mr Mueller declined to comment.

Mr Giuliani earlier told Reuters that Mr Trump would respond to questions about whether his campaign conspired with Moscow, not queries related to whether he sought to obstruct the probe while in office.

Among the topics the President covered was a June 2016 meeting between his son, Donald Trump Jr, other members of the Trump campaign team and a group of Russians, a source said told US media last week.

Mr Trump last year denied knowing about the Trump Tower meeting with the Russians, who had promised damaging information about Democratic rival Hillary Clinton. 

US intelligence agencies have already concluded that Russia interfered in the election in a bid to tip it toward Mr Trump by undermining Mrs Clinton.

Moscow has said it did not interfere in the election and Mr Trump has denied any collusion.

Mr Mueller has already brought charges against some former Trump aides, including his former campaign chairman and his former national security adviser, as well as a number of Russian individuals and entities.

-AP