President Barack Obama walked on a melting Arctic glacier, a river of ice, in Alaska Tuesday. The president is on a three-day visit to the state. The American leader is urging nations to act quickly to cut the release of gasses linked to climate change. The president called climate change the defining threat of this century. He said the world is “not acting fast enough.”.

Mr. Obama also called on the U.S. Congress to approve an earlier date for the delivery of a new heavy icebreaking ship costing $1 billion. The heavy ship is needed to ensure safe waterways in dangerous Arctic waters, which are also rich in resources. The U.S. has two such ships while Russia has 40.

Earlier, ministers from 11 countries and the European Union restated a commitment to take "urgent" action to slow the pace of global warming in the sensitive Arctic region. Officials from the U.S., France, South Korea, Singapore and other countries announced their promise in a joint statement at the GLACIER Conference in Alaska held by the U.S.