For the first time, China has sent three icebreakers to the Arctic, according to ship-tracking data, while a U.S. icebreaker, the USCGC Healy, aborted its mission after an onboard fire.

Despite China’s territory being 900 miles from the Arctic Circle, the nation has declared itself a “near-Arctic state” and has strengthened ties with Russia, raising concerns among other Arctic nations.

In response, the U.S. Department of Defense updated its Arctic strategy, emphasizing increased military presence and cooperation with allies, Newsweek has reported.

The Chinese icebreakers, including the Xue Long 2 and Ji Di, are actively operating in the Arctic, while the U.S. is working on extending the service life of its aging icebreakers and planning for next-generation replacements.

Written by B.C. Begley