The U.S. adminstration says it is ready to work with the new Ukrainian authorities / Photo by wikimedia.org

"We congratulate the people of Ukraine on today's voting in the parliamentary elections,” Stroh said, quoted by Russian news agency RIA Novosti.

“The voting took place despite policy and  security challenges in some parts of Ukraine, yet millions of voters across the country came to the polling stations to take part in voting."

Stroh added that Washington was "ready to work with Ukrainian President Petro Poroshenko and the new Rada (Ukrainian Parliament) and the government to meet together new challenges and to fulfil the aspirations of the Ukrainian people for a more secure, prosperous and democratic future."