HANOVER, Germany - Hanover Fair, the world's leading industrial trade show, opened on Sunday, as German Chancellor Angela Merkel stressed the importance of free trade.

Speaking at the opening of the fair, Merkel said that multilateral cooperation can add value for everyone. "That's why we are promoting global trade that is as free as possible," she said.

The German government is also to focus research capacities in artificial intelligence and better networking with the economy. Germany has to catch up in the field, where the United States and China are very active and investing much energy, Merkel said.

According to her, Germany's overall R&D investment will increase to 3.5 percent of the country's gross domestic product (GDP) by 2025.