US President Donald Trump has "no plan or intention" to change special counsel probing possible collusion in Russia's effort to sway the 2016 presidential elections.

The assurance came hours after special counsel Robert Mueller announced indictments against three Trump campaign aides, including former chairman Paul Manafort.

"The president said last week and I said several times before, there is no intention or plan to make any changes in regards to the special counsel," White House spokesman Sarah Huckabee Sanders said.