Poland said a number of Russian drones entered its airspace during an attack on Ukraine early Wednesday and were shot down with the help of NATO allies, a first since Moscow's full-scale invasion of its neighbor.

Leaders across Europe condemned the incident as the latest sign of escalation from the Kremlin, which has rebuffed President Donald Trump's bid to broker peace talks.

Poland's leaders spoke to their European counterparts afterward and Polish President Karol Nawrocki said that he spoke to Trump about the situation on Wednesday afternoon.

Russia labeled the accusations “groundless" and said it did not plan to attack any targets in Poland.

The Russian Defense Ministry said it had attacked the “military-industrial complex of Ukraine” in a "large-scale strike" but that "there were no targets envisioned for destruction on the Polish territory," pointing to the flight range of the drones it said it used against western Ukraine.

It said it was "ready to hold consultations with the Polish Ministry of Defense on this matter."

Polish Foreign minister Radosław Sikorski said there was no doubt the incursion was intentional, calling the violation an unprecedented attack on NATO and the European Union.

"In this case there were 19 breaches, and it simply defies imagination that it could be accidental," he told reporters.

The European Union needed to create a "drone wall" to face the challenges illustrated by the overnight incursion, he said.

"This is a threat not only to Poland, this new technology of the mass use of drones is a threat to all of the EU and nature and we need to face it together,” Sikorski added.

NATO allies offer support

Polish Prime Minister Donald Tusk said earlier that his country had dealt with "a large-scale provocation,” and that four of the 19 recorded drones were shot down.

Tusk added that a significant number of the drones flew in from Belarus, an authoritarian ally of Russia used as a launching pad for attacks on Ukraine.

“I have no reason to claim we’re on the brink of war, but a line has been crossed," he told the Polish Parliament. “This situation brings us the closest we have been to open conflict since World War II."

Belarus said the drones had “lost their way” and that it had also shot some down over its territory.

Poland's government held an emergency meeting with military leaders to discuss the drone incursion Wednesday.Kacper Pempel / Reuters

The Polish military’s operational command called the drones an “act of aggression," and initially urged residents to stay at home, with three eastern regions at particular risk. It later thanked NATO air command and the Dutch air force who it said scrambled F-35 fighter jets.

Poland and the United States are members of the North Atlantic Treaty Organization (NATO), which at its core is a mutual defense pact formed after WWII to deal with the threat posed by the Soviet Union, meaning an attack on one may be considered an attack on all.

Tusk said he had activated Article 4 of NATO’s treaty, under which alliance members can demand consultations with their allies, and that he was in touch with NATO Secretary-General Mark Rutte, who called the incursion "reckless behavior," irrespective of whether it was deliberate.

A NATO official confirmed to NBC News that Poland had "requested consultations under Article 4 of the Washington Treaty,” only the 8th time that the article — which does not trigger a military reaction — has been invoked since NATO was established in 1949.