A Russian and Chinese naval patrol consisting of several vessels operated off the coast of Alaska last week, defense officials and lawmakers said over the weekend -- a show of force that prompted a US military response but did not pose a threat to the US or Canada, a US Northern Command spokesperson told CNN.

NORTHCOM and the North American Aerospace Defense Command deployed planes and ships to monitor the Russian and Chinese patrol, which stayed in international waters, the spokesperson said.

Alaska's Republican Sens. Dan Sullivan and Lisa Murkowski said in a statement Saturday that a total of 11 Russian and Chinese vessels had been operating near the Aleutian Islands, and were met in response by four US Navy destroyers. Murkowski said that she and Sullivan had been in "close contact with leadership from Alaska Command for several days now and received detailed classified briefings about the foreign vessels that are transiting U.S. waters in the Aleutians."

Chinese Embassy spokesperson Liu Pengyu told CNN in a statement that "according to the annual cooperation plan between the Chinese and Russian militaries, naval vessels of the two countries have recently conducted joint maritime patrols in relevant waters in the western and northern Pacific Ocean. This action is not targeted at any third party and has nothing to do with the current international and regional situation."

Sullivan said that Chinese and Russian vessels came similarly close to Alaska last summer and were encountered by a US Coast Guard ship on a routine patrol at the time -- a "tepid" response, the senator added, that led him to press senior military leaders to be ready with a more robust response in the future.

"For that reason, I was heartened to see that this latest incursion was met with four U.S. Navy destroyers, which sends a strong message to (Chinese President) Xi Jinping and (Russian President Vladimir) Putin that the United States will not hesitate to protect and defend our vital national interests in Alaska," Sullivan said.

Russia and China have intensified their defense and economic partnership considerably since Russia invaded Ukraine in February 2022, according to a July US intelligence report, and the countries have repeatedly pledged to strengthen their military ties.