President Donald Trump says his White House will be “fighting all the subpoenas” issued by House Democrats in their investigations into his administration.

Mr Trump is criticising those investigations and telling reporters at the White House that he “thought after two years we’d be finished with it”.

Democrats have stepped up their inquiries in the aftermath of special counsel Robert Mueller’s investigation into Russian interference in the 2016 US election.

Mr Trump says “it’s enough” and that “we’re fighting all the subpoenas”.

One congressional subpoena the administration is expected to challenge has gone out to Don McGahn, former White House counsel who co-operated with Mr Mueller.

And the White House is pushing back on other fronts, including House Democratic efforts to obtain Mr Trump’s tax returns and his business’ financial records.

Mr Trump says he’ll go directly to the Supreme Court “if the partisan Dems” ever try to impeach him.

-AAP