BEIJING, June 17 (Xinhua) -- Chinese President Xi Jinping's trips to central and eastern Europe (CEE) this month will elevate ties between the 16 CEE countries and China, paving the way for successful projects under the "Belt and Road" framework.

Xi is scheduled to visit Serbia and Poland from June 17 to 21. He will then travel to Uzbekistan and attend the 16th meeting of the Council of Heads of State of the Shanghai Cooperation Organization (SCO) in Tashkent.

This is the Chinese president's second trip to the CEE in less than three months.

Even for Xi, whose globetrotting has already taken him to five continents in a little more than three years, such frequent visits to one single region are rare.

"This demonstrates the value China attaches to the '16+1' cooperation and to the collaboration between China and Europe in a more general sense," said Liu Zuokui, a CEE expert with the Institute of European Studies under the Chinese Academy of Social Sciences (CASS).

Xi visited the Czech Republic in late March this year. It was Xi's first trip to the CEE as China's top leader, and the first by a Chinese president ever to that European country.

Many saw the March trip as part of Xi's efforts to refine his new diplomacy push. Before March, Xi had already traveled to some 40 countries in the capacity of China's president, with CEE nations being an exception.

Still more saw it as a sign of closer links between China and the CEE, and the Serbian and Polish tours are set to strengthen that bond, they say.

"China and CEE countries share traditional friendship, which naturally draws the two sides closer and drives them forward in terms of cooperation," Liu said.

Serbia was the first CEE country to establish a strategic partnership with China, while Poland is China's largest trading partner in the CEE region.

Promoting bilateral cooperation with Serbia and Poland will "play an exemplary and positive role in propelling China-CEE relations," Liu said, adding that Xi's tours will bring China-CEE ties to a whole new level, he said.

Chen Xin, head of the economics division under the CASS Institute of European Studies, meanwhile, put Xi's CEE visits in the broader context of the still-warming Sino-European ties.

It has been 13 years since China and the European Unionestablished a comprehensive strategic partnership.

Despite some "recurring frictions", the two sides have successfully worked together in the face of the international financial crisis to advance global governance reform, stepped up communication and coordination on major international and regional issues, and contributed significantly to world peace, development and cooperation.

Economic links between China and Europe are perhaps the strongest glue holding the two sides together.

China is now the EU's second largest trading partner behind the United States, and the EU is China's biggest trading partner. According to Chinese customs figures, China's trade of goods with EU totaled 3.51 trillion yuan (533 billion U.S. dollars) in 2015.

But zooming in on China-CEE trade, the picture is less appealing.

Trade between China and CEE countries stood at 56.2 billion U.S. dollars in 2015. That figure is only about one tenth of the current China-EU trade.

"We have not fully tapped into the huge market potentials China and CEE countries hold," Liu Zuokui said.

Hopefully, CEE is catching up. Although two-way trade is relatively low at the moment, the growth rate is impressive. In 2010, China-CEE trade was only valued at 44 billion U.S. dollars. Earlier reports said China has plans to double its trade with the region by 2019.

"It signals a shift toward a more balanced approach in China's engagement with Europe," Chen Xin said.

Both Liu and Chen went on to note that Xi's visits will boost the China-proposed "Belt and Road" initiative.

"Serbia and Poland have considerable regional influence. Their support to the initiative is thus crucial to the proposed Belt and Road projects," Chen said.

This sentiment was echoed by Liu.

According to Liu, Serbia plays a key role in projects such as the China-Europe land-sea express passage, designed to strengthen connectivity and scale up trade between China and Europe, whereas Poland could serve as an important hub along the Silk Road Economic Belt.

So far, more than a dozen Chinese cities have launched regular freight train services linking them to Europe, and nearly all train rails pass through Poland, the eastern gateway to the European Union.

"Serbia and Poland hold the key to the vision of interconnectivity between Asia and Europe," Liu said.