According to U.S. Defense officials, a Russian fighter jet conducted an “unprofessional” intercept of an unarmed U.S. Navy surveillance aircraft over the Baltic Sea on Tuesday.

The U.S. Navy P-8 surveillance plane was flying in international airspace over the increasingly contested Baltic Sea when it was approached at high speeds by a Russian Su-27. The Su-27 flew to within only about 20 feet of the unarmed aircraft where it loitered for about nine minutes before breaking off and leaving the area.

The U.S. Navy does not formally characterize aircraft intercepts as professional or not, though multiple Navy officials described the interaction as such. The intercept was, however, formally classified as “safe,” as the crew of the P-8 were not placed in any imminent danger through the interaction.

The Department of Defense has yet to issue an official statement about the interaction that occurred only hours ago, though Lt. Cdr. Zach Harrell, a spokesman for US Naval Forces Europe, told was questioned about it this afternoon.

“US Navy ships and aircraft routinely interact with military units from other countries,” was all Harrell offered in response.

A similar intercept took place earlier this year, when another Russian Su-27 came to within five feet of a U.S. Navy EP-3 Orion surveillance aircraft. In that instance, the Su-27 crossed in front of the nose of the EP-3, forcing it to take evasive action to avoid a collision. That intercept was characterized as both unprofessional and unsafe, though the Russian military responded by claiming that their pilots behaved within the law and international norms.

They went on to challenge the American presence in the region, stating, “either exclude flying near Russian borders in the future or return to the negotiations table and agree on a set of rules for such flights.”

As for allegations of unsafe and unprofessional conduct that put American aviators at risk, Russia responded by suggesting the problem wasn’t Russian behavior, but rather the American’s mettle. In their statement, the Russian Ministry of Defense went so far as to suggest that Russian flying was causing “depression and phobias” among their American counterparts.