Censor.NET reports referring to the White House press service.
Despite "tough and difficult" relationship with the Kremlin, the U.S. will not stop trying to put pressure on Moscow in connection with its Ukrainian policy.
"Russia and separatists must lay down arms and stop bullying Ukraine," he said.
Obama also did not rule out the possibility that Russia may try to influence the outcome of the upcoming presidential election in the United States with the help of hacker attacks on the servers of the Democratic National Committee.
"A lot of countries out there are trying to hack into our stuff - governmental databases, private sector databases and non-for-profit databases," he said.
In addition, the American leader stressed that the U.S. is not going to stop trying to make sure that it can bring a political transition inside of Syria that can end the hardship there.
Earlier, the U.S. State Department noted that Russia's military build-up in occupied Crimea is not conducive to ending the conflict in Ukraine.
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