BRADLEY KLAPPERTROMSO, Norway (AP) â¿¿ 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.