Washington: US President Donald Trump has insisted for more than a year that Russians didn't try to get him elected. Special Counsel Robert Mueller put an end to those claims on Friday, declaring definitively that they did.

A federal grand jury indicted 13 Russian nationals and a so-called "troll farm" in St Petersburg on Friday for a broad campaign to sway the 2016 election in Trump's favor. The indictment alleges that the operation was funded to the tune of $1.25 million a month by companies controlled by a Russian businessman close to the Kremlin.

The indictment means that Trump can no longer credibly cast doubt on alleged Russian election meddling. His own national security adviser said Saturday that the evidence was "incontrovertible." And if he was still harboring dreams of firing US Special Counsel Robert Mueller or Deputy Attorney General Rod Rosenstein, something many Republicans already have warned against, such a move may be politically impossible.

Sergei Lavrov, Russia's foreign minister, speaks at the Munich Security Conference in Munich, Germany, on Saturday. Credit:Bloomberg

The White House seized on Rosenstein's declaration that Friday's indictment didn't allege "that any American had any knowledge" of the Russian interference, declaring "NO COLLUSION" in a statement. But the special counsel is still probing whether Trump or his campaign colluded with the Russians, a person familiar with the matter said.