Ukrainian President Petro Poroshenko's press service says there has never been any cooperation with controversial political consultant from the United States Paul Manafort.

"Petro Poroshenko's team has never cooperated with either Paul Manafort or his people. Proposals for cooperation came among others, however, they were not even considered," the presidential administration said, BBC News Russian reported.

This was the administration's comment on a statement by Manafort's ex-business partner Rick Gates, who testified in a U.S.-based federal court that their company, Davis Manafort Partners, Inc. (DMP), assisted Poroshenko in 2014.

"Gates said the last campaign he and Manafort worked in Ukraine was for the October Parliamentary election on behalf of the Opposition Bloc. DMP assisted Petro Poroshenko, and they were not paid in full," NBC News said on August 7.