Polish President Andrzej Duda (right) welcomes Chinese President Xi Jinping on Monday at the presidential palace in Warsaw. Poland is Xi's second stop on his three-nation tour to Eastern Europe and Central Asia. Photo AFP

China and Poland agreed Monday to upgrade ties to a comprehensive strategic partnership during Chinese President Xi Jinping's state visit to the country, a move experts believe is a breakthrough in Sino-European relations.

During a meeting between Xi and Polish President Andrzej Duda on Monday in Polish capital Warsaw, the two sides agreed to upgrade ties from the strategic partnership that was cemented in 2011.

"China and Poland regard each other as a long-standing and stable strategic partner, and see the other's development as an important opportunity for mutually beneficial and win-win results," said a joint communiqué signed by the two countries.

The two sides pledged to promote bilateral relations in an all-dimensional manner to benefit the two peoples by enhancing cooperation in politics, economy, society and culture, and expanding coordination and cooperation on global and regional affairs in a spirit of mutual respect, equal treatment and win-win cooperation, the document said.

The two sides are ready to push forward bilateral cooperation within the framework of Poland's sustainable development strategy and China-proposed "Belt and Road" initiative, which refers to the Silk Road Economic Belt and the 21st-Century Maritime Silk Road, said the communiqué.

"China's previous cooperation with Europe was mainly with Western European countries such as Germany and France, which are currently facing multiple crises and have become more conservative," Zhao Junjie, a research fellow at the Chinese Academy of Social Sciences European Institute, told the Global Times on Monday.

"Therefore, the comprehensive strategic partnership between China and Poland shows that China considers Central and Eastern European (CEE) countries as providing a  breakthrough in Sino-European relations, as well as the next new stable market committed to work together with China," Zhao said.

"Poland, the Czech Republic and Serbia form the chief axis and nucleus of the CEE, with which China will drive cooperation with the whole area," Zhao said, adding that Poland, as the most energetic country in the CEE, can work as a model to other nations.

On Monday, five Chinese companies signed memorandums of understanding (MoUs) with Polish counterparts in Warsaw, to deepen trade and investment partnerships in various sectors such as manufacturing and food exports.

The deals include one between Jiangsu Lantian Aerospace Industrial Park and Polish aerospace manufacturers Orka and PZL, and another between Chintex, a Chinese State-owned enterprise engaged in textiles and the trading business, and Polish dairy firm Mlekpol.

Poland is China's biggest trading partner of agricultural products in the CEE, Chintex Chairman Zhao Boya told the Global Times.

The deals were all signed during the Poland-China Business Forum organized by the Polish Information and Foreign Investment Agency, or PAlilZ, and the China Council for the Promotion of International Trade in Warsaw on Monday.

The food and beverage sector is one of the most important and fastest developing areas of the Polish economy, according to a report issued by PAlilZ on Monday.

"I think [Chinese investors] should invest in the food-processing industry," Slawomir Majman, president of the board of PAlilZ, said, noting that it is a booming industry in which Chinese firms will find more business opportunities in the near future.

The aviation, information and communications technology and renewable energy industries are expecting more Chinese foreign direct investment, which lags behind that of other countries like the US, Majman told the Global Times on Sunday.

China speaks highly of Poland's role in China-EU ties. Both sides support an early conclusion of negotiations on an ambitious and extensive China-EU investment agreement, which covers market assessment and investment protection.

Xi arrived in Poland on Sunday, the second stop of his three-nation Eurasia tour, which also includes Serbia and Uzbekistan.  

Xinhua contributed to this story