The Ukrainian conflict may hurdle the normalization of relations between the United States and Russia until it is fully settled, U.S. Secretary of State Rex Tillerson said.

"Until the full progress is made under the Minsk Accord, the situation in Ukraine will remain an obstacle to the improvement of relations between U.S. and Russia," Tillerson told a press conference in Moscow on Wednesday.

"Russia can make progress in the implementation by de-escalating violence and taking steps to withdraw separatist armed forces and heavy weapons, so that OSCE observers can fulfill their role," he said.