Russia and China have been organizing a joint patrol over the north pacific ocean and the Bering Sea off the coast of Alaska.
Both countries have conducted several joint patrols in the past, and Russia regularly flies its bombers over the Bering Sea.
But Wednesday's joint patrol was the first to bring together bombers from both Russia and China in the northern Pacific area.
Moscow and Beijing said the attack was "not aimed at any third party" while the US-Canadian Aerospace Defense Command (NORAD) said the bombers, which they intercepted, stayed in international airspace and were "not perceived as a threat."
But Alaska Senator Lisa Murkovski described the event as an "unprecedented provocation by our opponents," adding that "it was the first time they've been seen acting together."
China said the patrol had "no relation to the current international and regional situation.".
According to Russia, the Russian TU-95MS strategic missile carriers and xian H-6 strategic bombers of the Chinese air force took part in the patrol.
China and Russia have developed closer ties since Moscow was placed under sanctions by the West following the invasion of Ukraine in February 2022.
Earlier this month, Moscow and Beijing completed their fourth joint naval patrol in the north and western Pacific Oceans.
NATO countries issued a joint statement at the end of the recent summit in Washington accusing China of being a "decisive enabler" of Russia's war in Ukraine and urging it to "cut off any material and political support" for the country's war efforts.
In a report on Arctic security published Monday, the US Department of Defense expressed concern at the "growing lineup" of the two countries and predicted that their military cooperation will continue to grow.
Kremlin spokesman Dmitry Peskov dismissed this, saying Russian-Chinese cooperation in the Arctic can only contribute to an atmosphere of "stability and predictability" in the area.