In particular, Pifer said Ms Clinton could continue to support Kyiv, as well as the efforts of German Chancellor Angela Merkel in the Minsk process. It is likely she will retain economic sanctions against Russia as long as the Kremlin's stance does not change, reports.

In addition, Hillary Clinton may take a bit tougher stance against Russia, the expert believes. For example, the Clinton Administration, considering circumstances, may consider providing lethal aid to Ukraine, which the Obama Administration has refused to do earlier.

In case Donald Trump wins the poll, the U.S. policy can change not only toward Ukraine, but also toward NATO, looking back at some earlier statements of the Republican billionaire.

Read alsoClinton wants to investigate Putin and Assad's war crimes in SyriaPifer added that no matter the outcome of the U.S. presidential campaign, the new administration will have plenty of foreign policy issues to address. Whether Ukraine remains on top agenda, will largely depend on Kyiv’s attitude. The more vigorous the government will be in implementing reform and significant anti-corruption measures, the more likely Ukraine will be among Washington’s priorities, the expert added.