Premier Li Keqiang holds talks with German Chancellor Angela Merkel at the Great Hall of the People in Beijing, Oct 29, 2015. [Photo/Xinhua]

German Ambassador to China Michael Clauss says Merkel keeps "a very close friendship" with Chinese leaders, including Li.

When Li took office as prime minister in March 2013, Merkel was the first foreign leader to call and congratulate him.

In May 2013, Li chose Germany as one of the four legs in his first foreign visit as the premier.

In Merkel's last visit to China in July 2014, Li took her for a casual stroll at the Temple of Heaven in Beijing.

Three months later, Li visited Germany again and attended 12 events with the chancellor. After the meetings, Merkel took Li to a local supermarket so he could pick up postcards to send to his family.

Later, Li gave her a traditional Chinese puzzle called Lu Ban Lock, expressing his hope that the two countries could "solve difficulties with intelligence and foster a better future."

Her visit to Hefei for this trip is not "unexpected," Cui Hongjian, a researcher at the China Institute of International Studies and an expert on China-Europe relations, said.

Hefei is one of China's key science cities, with a heavy presence of the Chinese Academy of Science - a potential source of "intelligence support" for China and Germany's cooperation, Cui said.

Anhui already has strong ties with Germany, with German tire giant Continental Tires investing 150 million euros (160 million U.S. dollars) in a factory in Hefei in 2011, the company's first Asian factory.

As an inland province, Anhui will play an important role in the future development of urbanization and upgrading the manufacturing industry in China.

"There will be great potential for future cooperation with Germany," Cui said.