President Xi Jinping called for more cooperation with Serbia to benefit the people on both sides while visiting a Chinese-invested steel mill on Sunday.

Accompanied by Serbian President Tomislav Nikolic and Prime Minister Aleksandar Vucic, Xi traveled to the Smederevo Steelworks and talked with workers there. Founded in 1913, the Smederevo steel mill was acquired by China's?HeSteel Group for 46 million euros ($51.6 million) in April.

China would like to provide advanced technology as well as management experiences for Serbia to create more job opportunities and improve the people's livelihoods, Xi said.

Calling Serbia an important partner "on the same boat" with China, Xi said that the two countries have great potential to enhance cooperation, given that the bilateral relationship is based on deep traditional friendship.

The president's remarks came a day later after the two countries signed a joint declaration to lift the bilateral relationship to a Comprehensive Strategic Partnership, the first one of its kind in the Central and Eastern European region. The two countries signed more than 20 cooperative documents covering areas that include investment, economic and trade, people-to-people exchange and culture communications.

Located on a key point along the China-proposed Belt and Road route, Serbia could play an active role in implementing projects along the routes, Xi said.

Founded in 1913, the Smederevo steel mill went bankrupt in 2003, and then it was sold to US Steel for $23 million. Serbia became the owner of the steel mill once again in 2012 when the investor from the US withdrew. After the departure of US Steel, the country looked for a new investor.

Nikolic said that the workers in the steel factory will become richer and richer because the company is being managed by "friendly and just Chinese partners".

Vucic expressed gratitude for China's investment in Serbia, adding that he hoped more Chinese companies and investors would be interested in investing in major projects in Serbia.

"Thanks to President Xi Jinping and the Chinese company for bringing new hopes to the 5,000 workers at the steel mill," he said, adding that the country has been working hard to look for an investor for the factory in the past three years .

Stanuovic Lorica, 50, a female worker who spent 20 years in Smederevo, said that China's investment will bring more opportunities for the development of the century-old steel factory.

"We are glad to see that the links between the two countries are becoming closer, which has benefited common people like me," she said.

Ljubisa Obradovic, secretary of the association of the metal-electro industry, metal mines and metallurgy at the Serbian Chamber of Commerce, said the Serbian metal-electro industry gained a lot from Chinese investment.

"The arrival of HeSteel to Serbia opens huge potential in the metal-electro industry and mining in the sense that the level of production will double," he said.