US President Barack Obama arrived in Hanover on Sunday for the start of his visit to Germany. The premier of the northern German state of Lower Saxony, Stephan Weil, welcomed Obama before the president headed off for talks with German Chancellor Angela Merkel on global and security issues, dpa reported. Obama and Merkel will then officially open the annual Hannover Messe, the world's biggest industrial trade fair. The US will be fair's partner nation for the first time.