American military officials have said that a US Air Force reconnaissance aircraft encountered with a Russian fighter jet over the Black Sea last month.
The officials, who spoke on condition of anonymity, told CNN on Thursday that the two aircraft came within 10 feet of each other on May 30.
According to the officials, the Russian Sukhoi Su-27 fighter jet, flying at high speed, flew alongside the US RC-135 reconnaissance aircraft at the same altitude, broke off, and shadowed the plane before leaving the area.
ABC News reported that a top defense official described the encounter as "an unsafe intercept" by Russia.
The two superpowers are engaged in series of military encounters during the past months.
In another similar incident in April, the United States announced that US RC-135U was intercepted by a Russian SU-27 Flanker in an "unsafe and unprofessional manner."
Meanwhile, the Pentagon released a video earlier this month about a “routine encounter” of a Russian warplane and a US destroyer in the Black Sea.
The video showed a Russian warplane approaching from the distance and then quickly zooming past the American vessel.
Russian media reported the Su-24 aircraft forced the guided-missile destroyer USS Ross to change course when it was heading into Russia’s territorial waters.
The American destroyer was leaving the Romanian port of Costanta.
US Naval Forces Europe-Africa said in a statement the incident was routine and the warship never altered operations.
“Ross continued on her mission after observing the aircraft return to base,” said the statement. “At no time did Ross act aggressively nor did she deviate from her planned operations.”