Sen. Angus King, I-Maine, is traveling to Greenland this week to see the national security effects of climate change in the Arctic first hand.

King, who co-chairs the Senate's Arctic Caucus, is leaving Monday for the three-day trip with Coast Guard Commandant Adm. Paul Zukunft, as well as Danish defense officials. King's first day in Greenland will include a visit to the Jacobshavn Glacier, the country's largest and fastest moving glacier that lost five square miles over just two days last summer.

Later in the trip, King will tour the Danish Joint Arctic Command and participate in several briefings, according to a release from his office.

The Arctic is considered the next frontier in both commercial shipping and national security as ice melts and new waterways open up. The United States is underprepared compared to its neighbors who also have claims in the Arctic, such as Russia.

While many Arctic nations have fleets of icebreakers, the U.S. has only two: the Healy, a medium-class icebreaker primarily used for research, and the Polar Star, a heavy-class icebreaker that can plow through the thickest ice but will likely need to be retired by 2023.

Russia, by comparison, has 20 to 30 ships capable of breaking ice.

"The icebreaker is the highway of the Arctic," King told the Washington Examiner this year. "Right now the Russians have an interstate and we have an unpaved back road."

The administration's fiscal 2017 budget request included $150 million for the Coast Guard to begin design of a new heavy icebreaker and to gather interest from shipbuilders.

But the Senate Appropriations Committee did much more. The committee-passed bill would give the Coast Guard $1 billion to procure a new heavy icebreaker, though the full Senate has yet to pass the spending bill.

But Rep. Duncan Hunter, R-Calif., warned this year that even procuring a new heavy icebreaker on schedule would leave a years-long gap where the U.S. is lacking the critical capability to cut through the heaviest ice. If procurement begins in 2020, as the administration has requested, the new ship would not enter the fleet until 2024 or 2025, leaving at least a year gap with no heavy icebreaker.