Santa Claus could soon become a Russian citizen — and it's all because of global warming. That's the news from The New York Times' Andrew Kramer, who reports that last week, Russia formally claimed a vast region of the Arctic Ocean, including the North Pole.

In recent years, ice in the Arctic Ocean has rapidly melted, opening up vast areas that could contain undersea oil fields and large fisheries — and the Russian government wants those resources for themselves, Kramer reports.

“To base its claim, Russia in this region used a broad range of scientific data collected over many years of Arctic exploration,” the Russian Foreign Ministry wrote in a statement. “Submitting the claim...is an important step in formulating Russia’s right to the Arctic Shelf in accordance with the United Nations convention on the Law of the Sea.”

Under the 1982 U.N. Law of the Sea, a country can claim exclusive economic control over any part of the ocean above the continental shelf that sits next to its borders. Now, Russian president Vladimir Putin is claiming that the shelf extends another 150 miles further out from Russia’s shores than previously estimated. If the United Nations accepts Putin’s claim, Russia will control the Arctic Ocean up to 350 miles out from land, writes John Wentz for Popular Mechanics. That would expand Russia’s borders by about 463,000 square miles.

This isn’t the first time Russia’s laid claim to a wide swath of the Arctic: Putin tried to claim the territory back in 2002, but was rejected by the U.N. for lack of scientific evidence. This time, Russia is offering new data gathered by research vessels and even dispatched an Arctic explorer to dive beneath the North Pole in a submarine and plant a Russian flag on the ocean floor in 2007, writes Tom Parfitt for The Guardian.

Russia isn’t the only country trying to claim the resources locked beneath the Arctic Ocean: Denmark, Norway, Canada and the United States are all trying to gain a foothold near the North Pole, according to the Associated Press. The newly ice-free sea known as “the doughnut hole” is about the size of Texas and could hold up to a quarter of the world’s oil and gas reserves.

Environmental activists, however, aren’t happy with Russia’s claim. Vladimir Chuprov, Greenpeace’s Russian Arctic campaigner, said in a statement that “the melting of the Arctic ice is uncovering a new and vulnerable sea, but countries like Russia and Norway want to turn it into the next Saudi Arabia,” Kramer reports. The U.N. won't make a decision on the claim before 2016, but if any of these claims are accepted by the U.N., Santa’s workshop could be getting some new neighbors very soon.