President Obama on Friday called on Russian President Vladimir Putin to “move back” troops which have been massing on the border with Ukraine and begin negotiations with the government in Kiev.

“You’ve seen a range of troops massing along that border under the guise of military exercises but these are not what Russia would normally be doing,” said Obama in an interview from Europe with CBS News’ Scott Pelley.

“It may simply be an effort to intimidate Ukraine or it may be that they’ve got additional plans and in either case what we need right now to resolve and de-escalate the situation would be for Russia to move back those troops and to begin negotiations directly with the Ukrainian government as well as the international community.”

The U.S. and allies have slammed Russia's annexation of Ukraine's Crimean peninsula, but have been unable to convince Putin to stand down. The U.S. and European Union have instituted sanctions against a number of individuals, while only threatening measures targeting key sectors of the Russian economy if the Kremlin moves further into Ukrainian territory.

Obama on Friday flew to Riyadh, Saudi Arabia, after a weeklong visit to Europe where he sought to unite allies against Russia’s military incursion. But critics say that Obama must take more forceful steps to push Putin out of Crimea.

Reports this week said that Russian forces had been growing along the Ukrainian border, near parts of the country with large numbers of ethnic Russian citizens. Moscow has said it is just conducting military exercises, but international observers fear the Kremlin may attempt a new land grab. Putin has insisted that Moscow has a right to protect ethnic Russians in other countries.

In the interview, Obama was asked what Putin was after.

“If you can take him at his word,” Obama began — before being asked if the U.S. could do so with Putin.

“Well, on this I think he’s been willing to show a deeply held grievance about what he considers to be the loss of the Soviet Union,” he continued. “You would have thought that after a couple of decades, that there would be an awareness on the part of any Russian leader that the path forward is not to revert back to the kinds of practices that were so prevalent during the Cold War but in fact to move forward with further integration with the world economy and to be a responsible international citizen.

“He’s said that he considers the breakup of the Soviet Union to be tragic,” Obama added of Putin. “I think there’s a strong sense of Russian nationalism and a sense that somehow the west has taken advantage of Russia in the past and that he wants to in some fashion, you know, reverse that or make up for that.

“What I have repeatedly said is that he may be entirely misreading the west, he is certainly misreading U.S. foreign policy,” said the president. “We have no interest in encircling Russia. We have no interest in Ukraine beyond letting the Ukrainian people make their decisions about their own lives.”

Obama said the U.S. “rejects” the notion that there is a Russian sphere of influence along Ukraine’s borders that allows it to invade other countries.

“Because you are bigger and stronger, taking a piece of the country that is not how international law and international norms are observed in the 21st century,” he added.