Four fighter jets were launched by the U.S. Navy to intercept Russian warplanes that were flying one nautical mile away from the aircraft carrier USS Ronald Reagan.

According to White House spokesman Josh Earnest, the USS Ronald Reagan was performing a military exercise with South Korea in the Sea of Japan. Korean jets first intercepted the Russian warplanes. The Navy also stated they tried to communicate with the Russian planes, but never received a response.

Yahoo! News reports that Earnest stated the situation was “not a particularly threatening encounter,” as there was no evidence that the Russian planes posed any threat to the aircraft carrier or the ships that were escorting it.

The situation comes after an agreement was signed between Russia and the United States on October 10 that established protocols for flying over Syria. The agreement was to avoid any crashes between pilots.

Today’s incident isn’t the first time the U.S. and Russia has experienced encounters like this in 2015. A video was released by the Navy in June that showed Russian jets flying near the guided missile destroyer USS Ross. On July 4, Russian fighter jets located off the coasts of Alaska and California were intercepted by the United States, according to CNN.