Intrusions into NATO’s airspace blamed on Russia have reached an unprecedented scale, raising questions about whether the Kremlin is trying to test the alliance’s willingness to respond to a direct attack or divert its attention and resources from the war in Ukraine.

BRUSSELS — NATO is stepping up aerial surveillance in the Baltic Sea, while France, Germany and Sweden are bolstering Denmark’s air defenses ahead of two summits in Copenhagen this week over a series of troubling drone incidents near the country’s airports and military bases.

Sergei Lavrov has been highly critical of Western countries and Israel in his speech at the UN General Assembly.

Boosting NATO's presence close to Denmark sends "a message of assurance and cohesion within the Alliance," says a spokesperson.

Two NATO officials, who asked for anonymity to discuss sensitive operational matters, told NBC News U.S. fighter jets were taking off for assignments somewhere in Eastern Europe.

Russia's top diplomat accused NATO and the European Union of using Ukraine to declare a "real war" against his country in a speech at the United Nations on Thursday that Britain dismissed as "false fantasy world distortions.

President Donald Trump said on Tuesday that he believes NATO countries should shoot down Russian aircraft when they violate NATO airspace.

NATO and the EU have "declared war" on Russia through Ukraine, Russian Foreign Minister Sergey Lavrov claimed at a G20 foreign ministers’ meeting on Sept. 25. Lavrov’s remarks come amid rising tensions between Russia and NATO following recent violations of the alliance's airspace by Russian drones and fighter jets.

EU/NATO states are weighing a blockade or port denial strategy in the Baltic to counter Russia’s hybrid warfare and dark fleet operations.

Russia is becoming "more and more of a threat to NATO," German Defence Minister Boris Pistorius said on Monday, as he visited Poland and Lithuania amid weeks of high tensions on the alliance's eastern flank due to Russian incursions.