More Nato countries will move troops and fighter jets eastwards after more than a dozen drones entered Polish airspace on Wednesday.
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.
Tensions have been high across Europe since Poland accused Russia of an unprecedented incursion. Some of the 19 drones that entered Polish territory were shot down, while others crashed into fields and even a house in eastern Poland.
Warsaw said the incursion was deliberate, but Moscow downplayed the incident, saying it had “no plans to target” facilities in Poland.
Drones and missiles have occasionally veered into countries bordering Ukraine, including Poland, during Russia’s full-scale invasion – but this was the most serious incident of its kind since the war began in February 2022.
Polish Prime Minister Donald Tusk said it was “the closest we have been to open conflict since World War Two”.
Denmark will contribute two F-16 fighter jets to support Poland’s air defence, as well as a warship, its defence ministry said.
Danish Prime Minister Mette Frederiksen said: “We must not be naive. Putin will stop at nothing, and he is testing us. Therefore, it is crucial… Denmark is contributing to this.”
France has already said it will contribute three Rafale fighter jets, and Germany has pledged four Eurofighters.
The UK is “fully committed” to help strengthen the Eastern Sentry operation, the Ministry of Defence said in a statement, adding that it will provide more details soon.
On Friday, European countries and the US backed Poland during an urgent UN Security Council session in New York discussing the incursion.
“The United States stands by our Nato allies in the face of these alarming airspace violations,” acting US Ambassador to the UN Dorothy Shea said. “And rest assured, we will defend every inch of Nato territory.”
She noted that since US President Donald Trump and his Russian counterpart Vladimir Putin had held their peace summit in Alaska nearly a month ago, Moscow had intensified its bombing of Ukrainian cities and infrastructure.
European allies have said these large-scale aerial assaults indicated Putin had no interest in bringing the war in Ukraine to a close. Kyiv has itself probed deeper into Russian territory, hitting refineries, fuel depots and logistics hubs.
Kremlin spokesman Dmitry Peskov told reporters on Friday that there had been a “pause” in peace negotiations, blaming Ukraine’s European allies for “hindering” the process.
Trump – who has so far resisted calls for greater sanctions on Russia while pursuing a peace deal – also warned that his patience was “running out fast”.
He told Fox News: “It’s amazing. When Putin wants to do it, [Ukrainian President Volodymyr] Zelensky didn’t. When Zelensky wanted to do it, Putin didn’t.
“Now Zelensky wants to and Putin is a question mark. We’re going to have to come down very, very strong.”
While addressing the UN on Friday, Poland’s Secretary of State Marcin Bosacki held up photos of one of the downed drones and a house one had damaged.
“We know – and I repeat – we know that it was not a mistake,” he said.
But Russia continued to insist it had not targeted Poland, with ambassador to the UN Vasilly Nebenzia saying: “The maximum range of the drones used in this strike did not exceed 700 kilometers, which makes it physically impossible for them to have reached Polish territory.”
He said Moscow was willing to discuss the matter with Poland “if the Polish side indeed is interested in reducing tensions rather than fomenting tensions”.
Belarus – which sits between Poland, Russia and Ukraine, and is allied to Moscow – has previously said the drones had veered off course after their navigation systems were jammed.
The Netherlands and Czech Republic have already said they would send defences to Poland, while Lithuania will receive a German brigade and greater warning of Russian attacks on Ukraine that could cross into its airspace.
Meanwhile, Russia and Belarus began joint military drills on Friday, which they stage every four years.
They again rejected accusations that these posed a danger to neighbouring countries. The drills include exercises close to the border with Poland and Lithuania and in the Baltic and Barents seas.
