Italy has raised concerns over this month's elections after the release of a United States (US) intelligence report revealing a $300 million covert Kremlin influence campaign.

The fear of Russian influence, according to the State Department summary on the intelligence document review, might harm the chances of right-wing or populist parties with a history of strong relations with Russia, as well as politicians who have repeated Putin-friendly propaganda.

Italy's election is set on September 25.

According to final polls released on Saturday, a right-wing alliance led by the hard-right Brothers of Italy party, with 25 percent, was on track to win a solid majority of seats.

The leader of the right-wing League, Matteo Salvini, claimed he had never received any funding from Moscow. 

The League and the Putin-supporting United Russia party have a cooperation agreement.

Left-leaning legislators demanded that all parties and persons involved be identified prior to the vote.

The US State Department confirmed the existence of a diplomatic cable sent to US embassies that warned about Kremlin cash funneled to parties sympathetic to them around the world. 

The diplomatic cable, however, did not specify which countries and parties they are suspecting of having taken Russian money. 

Rome has been asking the U.S. for confirmation regarding whether Italy is mentioned in the dossier. 

Mario Draghi, the prime minister, spoke with US Secretary of State Anthony Blinken on Wednesday. 

Blinken's spokesperson stated in a readout that he "underscored the significance of continuing solidarity and opposition in the face of Russia's efforts to utilize energy and other measures to split countries that support Ukraine."

Luigi Di Maio, the foreign minister of Italy, "recommended prudence," stated that his country's representatives were "in regular contact with the US, for the sharing of information," and demanded an investigation.