US, Europe must impose sanctions on Russia: Barack Obama

President Barack Obama said Sunday the US and European countries should act collectively to impose sanctions on Russia for its actions in Ukraine.

"We're going to be in a stronger position to deter Putin when he sees that the world is unified, and the United States and Europe are unified, rather than this is just a US-Russian conflict," Xinhua quoted Obama in a joint press conference after meeting Malaysian Prime Minister Najib Razak here Sunday.

Obama said although an international agreement was signed to de-escalate the crisis, Russia did not lift a finger to help.

"In fact, there is strong evidence that they (Russia) have been encouraging the kinds of activities that have taken place (in Ukraine)," he said.

Obama is on a three-day official visit to Malaysia since Saturday.