U.S. President Donald Trump on Thursday scornfully rejected "disgusting" talk among Democrats about launching an impeachment inquiry against him in the aftermath of the Russia probe, saying he did nothing to merit such an outcome.

Talking to reporters on the White House South Lawn ahead of a trip to Colorado, Trump grew animated in reacting to a statement from U.S. special counsel Robert Mueller on Wednesday.

Mueller said his report on Russian collusion in the 2016 presidential campaign did not clear Trump of obstruction of justice and indicated it was up to Congress to decide whether he should be impeached.