Tensions between the United States and Russia further escalated on Monday after a Russian fighter jet intercepted a U.S. Navy reconnaissance aircraft flying over the international waters of the Black Sea. With both a large scale NATO deterrence exercise ongoing and Russian ballistic missile tests expected any day in the region, the Russian fighter executed what were characterized by American Defense officials as “unsafe and unprofessional” maneuvers in the vicinity of the American aircraft.

The encounter, which lasted a total of nearly 25 minutes, occurred when a Russian-flagged Su-27 Flanker conducted a high-speed pass directly in front of a U.S. Navy EP-3 Aries II. The Russian fighter then circled back and closed with the unarmed American aircraft a second time. On the second pass, the Russian jet engaged its afterburner as it crossed in front of the EP-3, creating violent turbulence likely intended to force the aircraft to adjust its course. While these intercepts are not uncommon, this intercept takes place during the largest NATO exercises held in the Arctic since the Cold War, prompting aggressive Russian rhetoric and a heightened alert status for military forces on both sides.

“A U.S. EP-3 Aries aircraft flying in international airspace over the Black Sea was intercepted by a Russian Su-27. This interaction was determined to be unsafe due to the SU-27 conducting a high speed pass directly in front of the mission aircraft, which put our pilots and crew at risk,” the U.S. Navy said in a press release on Tuesday.

“The intercepting Su-27 made an additional pass, closing with the EP-3 and applying its afterburner while conducting a banking turn away. The crew of the EP-3 reported turbulence following the first interaction, and vibrations from the second. The duration of the intercept was approximately 25 minutes.”

Thus far, Defense Department officials have chosen not to release any estimates regarding how close the Su-27 came to the Navy plane as it crossed its nose, but in footage released by the Department of Defense, it’s clear that the Russian fighter came far closer than the Navy pilots likely would have preferred.

The Pentagon did not take issue with Russia’s operating fighter jets in the region, pointing out that the EP-3 Aries was operating in international airspace where the Russians also have the right to conduct security operations. They did, however, take Russia to task on the behavior of their pilot, which U.S. officials called “irresponsible.”

“While the Russian military is within its right to exercise within international airspace, this interaction was irresponsible. We expect them to behave within international standards set to ensure safety and to prevent incidents, including the 1972 Agreement for the Prevention of Incidents On and Over the High Seas (INCSEA). Unsafe actions increase the risk of miscalculation and potential for midair collisions,” the statement reads.