Poland will deploy more troops at the border with Belarus after it accused Minsk of violating its airspace, raising tensions between the NATO member and a key Kremlin ally in an increasingly volatile security landscape in Europe. Warsaw said two Belarusian helicopters allegedly violated the Polish airspace during training exercises on Tuesday, which the Belarusian defense ministry vehemently denied and dismissed as “far-fetched.” This came amid increased activity near a thin strip of land between Poland and Lithuania, known as the Suwalki gap or corridor, which troops from the Russian mercenary group Wagner are moving toward in an apparent attempt to increase pressure on NATO and EU members. Belarusian leader Alexander Lukashenko brokered a deal to cap Wagner’s failed rebellion against Moscow, after which thousands of mercenary fighters were reportedly sent to Belarus. Minsk had informed Warsaw about the exercise, but a border crossing took place in the eastern Bialowieza region at a “very low altitude, making detection by radar systems difficult,” the Polish defense ministry said in a statement. Polish Defense Minister Mariusz Blaszczak subsequently ordered that more troops and combat helicopters be deployed along the border, the ministry added. The Belarusian defense ministry said “there were no violations of the airspace by the Mi-24 and Mi-8 helicopters.” “The accusations of violating the border of Poland by the Mi-24 and Mi-8 helicopters of the Belarusian Air Force and Air Defense Forces are far-fetched and were made by the Polish military-political leadership to justify the build-up of forces and means near the Belarusian border,” the ministry said on Telegram. Risk of ‘full-scale war’ Poland informed NATO of the incident, which allegedly took place south of the Suwalki gap, a 60-mile line that is strategically significant to NATO, the EU, Russia and Belarus. The border region links the Russian enclave of Kaliningrad to Belarus and it is the only overland connection between the Baltic states and the rest of the EU. Last week, Polish Prime Minister Mateusz Morawiecki said Wagner mercenaries were heading towards the Suwalki corridor via Grodno, a city in western Belarus, in a situation that is “becoming even more dangerous” as Russian-allied forces attempt to increase their presence near the NATO border. On Tuesday, the Polish Deputy Foreign Minister Paweł Jabłoński told local radio station RMF.FM that there could “unfortunately” be more provocations from Belarusian and Russian forces in the future. Martin Smith, a senior lecturer in defense and international affairs at the Royal Military Academy Sandhurst (RMAS) in southern England, said Lukashenko “feels the need” to publicly declare his support for Russia because he has avoided direct participation in the war in Ukraine. “Ratcheting up tensions with neighboring NATO members is one of the ways he chooses to do this. It’s a diplomatic game he plays with some skill, the skill being in calibrating the escalation of tensions so that there is no major threat of escalation to active hostilities,” Smith told CNN. He said he is “skeptical” about the Belarusian leader’s proposed joint military exercises with Wagner forces. “After the Wagner mutiny in Russia in June, President Lukashenko will be very aware that (Yevgeny) Prigozhin and his troops in Belarus could turn against him too at some future point,” Smith said. “It is therefore in his interest to keep the actual Wagner presence in his country small and low-level, while at the same time using it to extract propaganda value in relations with NATO countries. I believe this is what he is doing here. In reality I think Lukashenko will want to keep Belarus’s army firmly under his own control and not cede anything significant to the Wagner Group,” Smith added. Barbara Yoxon, a lecturer in international politics at Lancaster University in northern England, said Warsaw “views Belarus as complicit in the current European security crisis.” Moscow used Belarusian territory to facilitate its invasion of Ukraine in February 2022, strengthening ties between Putin and Belarusian leader Alexander Lukashenko. “Deploying troops to the Suwalki gap would provide a direct link between Russia and Kaliningrad, which makes it a vitally important target for Putin’s regime,” Yoxon told CNN. “By deploying troops from both the west (Kaliningrad) and the east (Belarus), Russia would be able to effectively cut off the Baltic States from its NATO allies in central and western Europe. This would allow Putin to potentially invade countries like Lithuania, Latvia, or Estonia.” The war in Ukraine prompted Western leaders of the bloc to rethink their national security strategy in the face of Putin, who has historically tried to erode NATO expansion in Europe. “If Russia deployed troops to the Suwalki gap, it would likely trigger an immediate military reaction from other NATO countries, which would see it as a direct attack on its member states in the region,” Yoxon added. “Such a move would signal that Russia is ready to escalate its confrontation with NATO to a full-scale war and risk a nuclear escalation on both sides.” Diplomatic spat Separately, Warsaw summoned the Ukrainian ambassador to Poland on Tuesday after a Polish foreign policy adviser accused Kyiv of being ungrateful for Poland’s support in exporting its grain. In July, Russia withdrew from a deal that allowed for the safe passage of Ukrainian grain from southern ports in the region, spiking wheat prices and putting pressure on countries in the Global South that rely on the crucial export. Five EU countries, four of whom border Ukraine – Poland, Slovakia, Hungary, Romania and Bulgaria – lifted sanctions on the import of Ukrainian grain, which they had installed to protect their own agricultural industries. But on Tuesday, Kyiv called on the Polish ambassador to Ukraine after the head of the Presidential Office for International Policy, Marcin Przydacz said on Monday it should, “start appreciating what role Poland has played for Ukraine over the past months and years.” Kyiv said that “statements about the alleged ingratitude of the Ukrainians for the assistance of the Republic of Poland do not reflect reality and as such are unacceptable.” It added that Ukraine and Poland’s friendship runs “far deeper than political pragmatism,” stressing that “no statements will prevent us from jointly fighting for peace and building a common European future.” This story has been updated.