Russia's troops in Ukraine's Crimea / Photo from UNIAN

"At the moment, it's not obvious the path that Georgia and Ukraine were taken to NATO while they still have Russian troops on their soil. Our immediate objective should be to bring enough pressure to bear on Russia so that they leave those lands, that they give back Crimea to Ukraine and leave eastern Ukraine and northern Georgia," he said in Washington, D.C., in remarks at a discussion on Russia's military strategy in Europe and violation of the 1987 Intermediate-Range Nuclear Forces (INF) Treaty.

Read alsoRussia sanctions to remain until settlement of Ukraine, Syria conflicts - TrumpIn his words, U.S. Secretary of State Rex Tillerson's outcome of the bilateral meeting in Hamburg was very clear that "the sanctions we put in place on Russia will remain in place as long as there are Russian troops on Ukrainian soil."

"Of course Russia is trying to destabilize and divide the west. That's what they have been doing for decades," he said.

"They did it in 1983 when they helped fund those massive protests against the deployment of INF forces to Europe and they are doing it today, in the elections in Western Europe and in our elections here. They are doing it through snap military exercises or increasingly bellicose rhetoric. This is simply what Russia does. That's why we have to meet this kind of provocations with a firm and unyielding response," he said.