MURMANSK, Russia—Melting ice in the Arctic Ocean is bringing a centuries-old dream closer to reality for Russia: a shipping passage through its northern waters that could put it at the center of a new global trade shipping route.

After one of the warmest years on record, the Kremlin is near to realizing its controversial plans for a global shipping route in its high north—plans that have put Moscow at odds with the U.S. and could create friction with China, two countries that also have designs on the Arctic.

Warming in the Arctic is happening twice as fast as the rest of the planet. Last year, ice coverage reached some of the lowest levels ever recorded, and it is only expected to shrink further in 2021. That is pushing Moscow to build infrastructure along the route, which can cut the distance of trips between Europe and Asia by a third compared with shipping through the politically fraught South China Sea or congested Malacca Straits currently used for cargo.

This year’s shipping season on the passage, which spans Russia’s expansive Arctic coast, started earlier than ever before, in February, when the liquid natural gas carrier Christophe de Margerie sailed from China to the northern Yamal peninsula. The voyage followed an unprecedented nearly eight-month shipping season last year, giving Russia a taste of what the future could hold for the Northern Sea Route if traffic continues to grow.

A host of issues remain, such as icebreaker escort tariffs, transit costs and navigational unpredictability in the Arctic Circle. But an opening of the passage would put Russia at the center of a new global shipping route for energy supplies and cargo. Moscow says it has the right to restrict passage and set prices for transit, and the route would also give it an important bargaining chip in its ties with China—one of the biggest beneficiaries of the 3,500-mile long passage.