Putin calls Obama to discuss Ukraine

Russia's Vladimir Putin has telephoned President Barack Obama to discuss the US proposal for a diplomatic solution to the crisis in Ukraine. Mr Obama suggested that Russia put a concrete response in writing, the White House said in a statement. According to the Kremlin, Mr Putin suggested examining how the situation could be stabilized. Russia's annexation of Crimea from Ukraine has sparked international condemnation. In the hour-long phone call, the US president urged Mr Putin to avoid the build-up of forces on the Russian border with Ukraine.