Ukraine's Western-backed leader Petro Poroshenko promised to meet Russia's Vladimir Putin and involve US President Barack Obama in his stalled push for peace.
The authoritarian leader of Belarus flew into Kiev hoping to revive stalled Ukrainian peace talks he has been hosting to calm Europe's volatile eastern edge.
President Bashar al-Assad met a top Russian envoy who said Moscow is hoping to relaunch peace talks for the war-torn country and could host a Syria-US meeting.
NATO accused Russia of sending tanks, troops to east Ukraine, raising fears of renewed all-out fighting and calling into question the Minsk peace deal.
John Kerry called for a resumption of Israeli-Palestinian peace talks, saying both sides had to be helped to make "tough choices" for lasting stability.
In order to stop the bloodshed and stabilise the situation in southeast Ukraine, I believe that the parties to the conflict should immediately agree on and coordinate the following steps: Vladimir Putin.