U.S. Sen. Maine Angus King says his military excursion to the Arctic underscores the need for the United States to take immediate action against global climate change.

King arrived in the Arctic on Saturday night to meet with Navy officials about their ability to operate in the warming Arctic environment.

The U.S. says the Arctic is a region important to national security, and the senator says the trip will help him make better decisions in Congress through his position on the Armed Services Committee. The Navy trains in the challenging environment every three years to test combat readiness.

King says while addressing climate change should be a priority, the U.S. also should be pragmatic about the opening of largely unchartered and unclaimed waterways to new avenues of commerce and exploration.