In comments posted on Russia's Facebook equivalent VKontakte, Prigozhin said: "We have interfered (in U.S. elections), we are interfering and we will continue to interfere. Carefully, accurately, surgically and in our own way, as we know how to do."
The remark was posted on the eve of the U.S. midterm elections in response to a request for comment from a Russian news site.
"During our pinpoint operations, we will remove both kidneys and the liver at once," Prigozhin said. He did not elaborate on the cryptic comment.
In July, the U.S. State Department offered a reward of up to $10 million for information on Prigozhin in connection with "engagement in U.S. election interference". He has been hit by U.S., British and European Union sanctions.
Prigozhin, who is often referred to as "Putin's chef" because his catering company operates Kremlin contracts, has been formally accused of sponsoring Russia-based "troll farms" that seek to influence U.S. politics.
In September he admitted to founding the Kremlin-aligned Wagner Group mercenary group, which is active in Syria, Africa and Ukraine. Last Friday it opened a defense technology center in St Petersburg, a further step by Prigozhin to highlight his military credentials.