Sanctions on Russia must remain in force until it adheres to the Minsk agreement, U.S. President Barack Obama said, during a press conference at the White House.

"We agreed that sanctions on Russia need to remain fully in force until Russia complies fully with its obligations [regarding Ukraine]," Obama said.

"Along with our NATO allies, we'll keep bolstering our presence in central and Eastern Europe – part of our unwavering Article 5 obligation to our collective defense. We will continue to work with the IMF and other partners to provide Ukraine with critical financial support as it pursues economic and anti-corruption reforms," the U.S. leader said.

Obama stressed that if the Russian authorities don’t change their policies towards Ukraine, Russia will face serious problem.

"If Russia continues on its current course – which is ruining the Russian economy and hurting the Russian people, as well as having such a terrible effect on Ukraine – Russia's isolation will only worsen, both politically and economically," he said.

"And as diplomatic efforts continue this week, we are in absolute agreement that the 21st century cannot stand idle and simply allow the borders of Europe to be redrawn at the barrel of a gun," the president stressed.