He said this in an interview to The New York Times, Censor.NET informs referring to Ukrinform.
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Obama stated that the prospects for a diplomatic agreement that would prevent President Vladimir V. Putin of Russia from invading Ukraine were real, but dimming.
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"A deal should be possible," Mr. Obama said. However, he added, "we are at a dangerous time, in part because the position of the separatists has weakened. I think Putin does not want to lose face, and so the window for arriving at that compromise continues to narrow."
"He could invade," Mr. Obama said.