The efforts were carried out together with the British fleet and the aim was "to ensure the freedom to navigate and (at the same time) show the seamless cooperation between allies", according to the US Navy.
Another reason, according to US sources, is that the Chinese and Russian military are increasingly examining the US military's ability at sea and in the air during the corona pandemic.
The US operation included three warships and one support vessel. Russia has been informed of the effort, according to the Pentagon.
The exercise follows a US exercise last week in the increasingly conflict-ridden South China Sea, where China is expanding its claims.