More Nato countries will move their troops and fighter jets eastwards in response to Wednesday's unprecedented Russian drone incursion into Polish airspace.
Denmark, France and Germany have joined a new mission to bolster the military alliance's eastern flank. Other Nato allies are expected to take part later.
It came as the Kremlin said on Friday that peace talks with Kyiv were on "pause", with spokesman Dmitry Peskov saying: "You can't wear rose-tinted glasses and expect that the negotiation process will yield immediate results."
Political tensions have been high across Europe after Poland said 19 Russian drones had flown through its airspace on Wednesday. Some were shot down, while others crashed into fields and even a house in eastern Poland.
Russia's military said it had "no plans to target facilities" in Poland - but Polish and European leaders believe the incursion was deliberate.
