"Yesterday I received a document stating that the side of prosecution will not file any arguments with the Supreme Court as an objection to the petition we filed," Tarasov told reporters.
He added that it meant that if the Supreme Court would accept the case then "it would only see the arguments of the defense."
In February, Tarasov explained that the chances of the US Supreme Court accepting the case for review are generally extremely low — around 1% acceptance rate when the case is filed by the defendant himself, and around 5% chance when the case is filed by the paid legal defense.
Bout was arrested in Bangkok in 2008 in a joint operation between Thai and US authorities, who accused him of conspiring to kill Americans by allegedly agreeing to supply Colombian militants with weapons.
Moscow has said that the case has been politicized and has repeatedly called on Washington to release the Russian citizen, who is serving a 25-year sentence in the United States.