Talks about the U.S. debt cap need to be more mature, says a German minister.

There isn't much time left to reach a deal. Earlier this month, U.S. Treasury Secretary Janet Yellen said that if a deal isn't reached, the biggest economy in the world could default on its debt on June 1.

Leaders of the Democratic Party want to raise the cap, but Republican lawmakers want to agree on spending cuts first.

Christian Lindner, the German finance minister, hopes that American politicians will be "m....