The kit kept subjects reasonably warm for six hours in temperatures that dropped below minus 65.
The Navy is moving to expand its presence in the Arctic.
Walruses are monstrously large animals that can weigh up to a few thousand pounds and can be quite ferocious when threatened.
Sailors are sweeping for explosives in the depths of frigid Arctic waters as they prepare for a new kind of fight.
Military and intelligence officials outlined a range of long-term threats arising from climate change.
The Navy's 2nd Fleet has reached initial operational capacity, its commander announced Wednesday.
Bolton said the Coast Guard also will play an important role as the administration pressures Cuba, Venezuela and Nicaragua.
The drones could be programmed to "follow strategic assets," including Norwegian or ally submarines.
The Trump administration warned China and Russia that the U.S. won't stand for aggressive moves in the Arctic region.
The service aims to work with partners to promote visibility and ensure stability in the region.