TROMSO, Norway (AP) ― U.S. Secretary of State Hillary Rodham Clinton on Saturday ventured north of the Arctic Circle and urged international cooperation in a region that could become a new battleground for natural resources.

On her trip to the northern Norwegian city of Tromso, she conveyed that message of working together in one of the world’s last frontiers of unexplored oil, gas and mineral deposits. The region is becoming more significant as melting icecaps accelerate the opening of new shipping routes, fishing stocks and drilling opportunities.

To safely tap the riches, the U.S. and other countries near the North Pole are trying to cooperate to combat harmful climate change, settle territorial disputes and prevent oil spills.

“The world increasingly looks to the North,” Clinton told reporters after a two-hour boat tour of the nearby Balsfjord and meeting with Arctic scientists. “Our goal is certainly to promote peaceful cooperation,” she said, adding that the U.S. was “committed to promoting responsible management of resources and doing all we can to prevent and mitigate the effects of climate change.” 

At the least, the U.S. and the other Arctic nations hope to avoid a confrontational race for resources. Officials say the picture looks more promising than five years ago when Russia staked its claim to supremacy in the Arctic and its $9 trillion in estimated oil reserves by planting a titanium flag on the ocean floor.

The United States does not recognize the Russian assertion and has its own claims, along with Denmark, Norway and Canada, while companies from Exxon Mobil Corp. to Royal Dutch Shell PLC want to get in on the action. China also is keeping a close eye on the region.

Moscow has eased tensions somewhat by promising to press any claims through an agreed U.N. process. But Washington has yet to ratify the 1982 Law of the Sea treaty regulating the ocean’s use for military, transportation and mineral extraction purposes.

With 160 countries having signed on, the Obama administration is making a new push for U.S. Senate approval. Refusal puts the U.S. at risk of getting frozen out of its share of the spoils.

Arguing for its ratification at a recent Senate hearing, Clinton said the treaty would offer the U.S. oil and gas rights some 600 miles into the Arctic. She said American companies were “equipped and ready to engage in deep seabed mining,” but needed to join the treaty to take exploit oil, gas and mineral reserves.

On Saturday, in the eight-nation Arctic Council’s home city, she stressed that the international agreement “sets down the rules of the road that protect freedom of navigation and provides maritime security, serving the interest of every nation that relies on sea lanes for commerce and trade.”

The Arctic’s warming is occurring at least twice as fast as anywhere else, threatening to raise sea levels by up to 5 feet this century and possibly causing a 25 percent jump in mercury emissions over the next decade. The changes could threaten polar bears, whales, seals and indigenous communities hunting those animals for food, not to mention islands and low-lying areas much farther away, from Florida to Bangladesh.

The changing climate also is changing the realm of what is possible from transportation to tourism, with the summer ice melting away by more than 17,000 square miles each year. During the most temperate days last year, only one-fifth of the Arctic Circle was ice-covered. Little of the ice has been frozen longer than two years, which is harder for icebreakers to cut through.

Europeans see new shipping routes to China that, at least in the warmth and sunlight of summer, are 40 percent faster than traveling through the Indian Ocean, the Suez Canal and the Mediterranean Sea. A northwest passage between Greenland and Canada could significantly speed cargo traveling between the Dutch shipping hub of Rotterdam and ports in California.

The Arctic Council is hoping to manage the new opportunities in a responsible way. It includes former Cold War foes U.S. and Russia, but Norwegian Foreign Minister Jonas Gahr Stoere said governments were prepared to deepen cooperation “in a region that used to be frozen, both politically and climatically.”

“Now there is a thaw,” he said.

Last year in Greenland, Clinton and her counterparts from other nations took a small step toward international cooperation by agreeing to coordinate Arctic search-and-rescue missions for stranded sailors and others.

Officials are now trying to enhance the cooperation, including through joint plans to prevent oil spills in an environment that would make cleanup a logistical nightmare.

The U.S. has been championing measures such as shifting away from dirty diesel engines, agricultural burning and hydrofluorocarbons to lessen the effect of short-lived greenhouse gases that are a particularly potent source of climate change in the Arctic.