Washington, Sep 3

Barack Obama has become the first serving US president to cross the Arctic Circle on a visit to the Eskimo village of Kotzebue.

Obama, who focused his visit to Alaska on the fight against climate change, wrapped up his trip in the little town of 3,200 residents, most of them Alaskan Native Americans, and the western coast of the largest US state.

"I couldn't be prouder to be the first (president to travel to the Arctic) and to spend some time with all of you," Obama, in the gymnasium of Kotzebue School, told many of the assembled townspeople.

He delivered a speech in which he once again insisted on the need to act quickly and on a global level against climate change.

"I've been trying to make the rest of the country more aware of a changing climate, but you're already living it," Obama told a crowd of more than 1,000.

"Think about it. If another country threatened to wipe out an American town, we'd do everything in our power to protect it. Well, climate change poses the same threat right now. And that's why I care so deeply about this."

Global warming has significantly affected Alaska, where the average temperature has already risen by more than 3 degrees Celsius over the past 50 years, causing - among other things - substantial melting of glaciers, a situation that contributes to a rise in sea level all over the world.

The increase in sea level puts many towns on the Alaskan coast, and especially in the Arctic - including Kotzebue - in jeopardy.