US and Russia agree to keep talking amid tensions over Ukraine

Antony Blinken, left, greets Russian foreign minister Sergey Lavrov (AP)

Top US and Russian diplomats have agreed to keep talking amid the stand-off over Ukraine, despite a summit in Switzerland producing no movement on the crisis.

There are fears that Russia will invade Ukraine after Moscow massed tens of thousands of troops at the border, while the west has ramped up supplies of weapons to Kyiv.