United States Secretary of State Marco Rubio announced on 31 October that the US, Japan, and South Korea have signed a memorandum of cooperation on the Arctic, committing the three nations to keeping the region open to peaceful commerce and free from coercion. The announcement came at the close of the G20 foreign ministers' meeting in Atlanta, following a dedicated trilateral session among the three countries' top diplomats.

What the Memorandum Covers

Rubio described the agreement's central purpose as ensuring that the Arctic 'remains a region free of dominion or coercion and that it instead remains a place of peaceful relations and commerce.' The memorandum was framed as part of a broader set of diplomatic engagements held on the sidelines of the G20 gathering, where energy access, supply chain resilience, and freedom of navigation were among the headline concerns.

Rubio did not disclose specific projects, funding commitments, or an implementation timetable at the press conference. The agreement's operational provisions were not outlined publicly, leaving its mechanics subject to further diplomatic detail.

The Greenland Dimension

Separately, Rubio defended a distinct arrangement concerning Greenland, saying it addressed US national security imperatives while also protecting the interests of Canada and other NATO allies. When asked about differing perceptions of the deal in Denmark and Greenland, Rubio said he was unfamiliar with the specific comments being cited and had not followed their coverage in Denmark.

'Suffice it to say we have a very good deal. One the president is fully advised of. He understands and is very supportive of,' Rubio said.

He presented the Greenland arrangement as building on longstanding US activity in the territory. One of its stated purposes, he said, was to prevent a potential adversary from gaining access through commercial means in ways that could harm the countries involved. Rubio added that these protections were designed to endure regardless of whether Greenland chose independence or remained part of the Kingdom of Denmark.

Greenland's Strategic Importance

Rubio underscored that Greenland's geographical position was central to President Trump's longstanding interest in the territory. Its strategic value, he said, extended well beyond missile defence to broader developments unfolding across the Arctic.

'It has always played a critical role in national security. It is more pronounced now, not just because of defences against missiles, but because of the Arctic,' he said. He described the Greenland arrangement as lasting in perpetuity and said its benefits extended to Canada and other NATO partners.

G20 Atlanta: Broader Economic Agenda

Rubio used the Atlanta forum to emphasise the economic focus of the US G20 presidency. He said the ministerial meeting had addressed access to energy, critical minerals, and reliable supply chains as issues that would shape the global economy over the coming decades. Countries also used the sidelines for bilateral meetings, with Washington pursuing cooperation on maritime security and infrastructure alongside its multilateral commitments.

This comes amid growing geopolitical competition in the Arctic, where melting sea ice is opening new shipping lanes and resource extraction opportunities, drawing intensified interest from major powers including Russia and China. The trilateral memorandum signals a coordinated Western-aligned push to shape the region's governance before those dynamics solidify.