US media have reported that Russia has covertly given at least 300 million dollars since 2014 to political parties, politicians and officials in more than two dozen countries.
The New York Times and other outlets cited a State Department summary of a recent US intelligence review in reporting on Tuesday on what the media call Russia's bid to exert political influence.
The reports say organizations and individuals close to the Russian administration of President Vladimir Putin gave out the funds in covert efforts to shape political environments in Moscow's favor and weaken democracies.
They say the Russian ambassador in one Asian country gave millions of dollars in cash to a presidential candidate.
In another case, a Russian business figure tried to use pro-Russian think tanks in Europe to support far-right nationalist parties.
Such flows of money reportedly increased from 2014, when the United States imposed sanctions on Russia over its annexation of Crimea in southern Ukraine.
The reports say Russia plans to transfer hundreds of millions of dollars more.
State Department spokesperson Ned Price said on Tuesday that what the Russians are doing for election meddling around the world is "an assault on sovereignty."
Price said the US is discussing with its partners in various countries about how to put an end to Russia's meddling.