President Xi Jinping says China wants to deepen its relations with Serbia as the two countries signed a series of agreements, reflecting the Asian power's efforts to boost its presence in the Balkans.

Xi on Saturday signed a declaration on strategic partnership with Serbia's President Tomislav Nikolic. He also oversaw the signing of 21 agreements and memorandums ranging from economy, infrastructure, energy and finance to defense industry, technology, culture and media.

Xi said "the development of our relations is based on big projects." He added that Serbia holds an important position in China's "One Belt, One Road" initiative — a sweeping plan to deepen trade relations and open new markets.

Xi also said China supports Serbia's bid to join the European Union.