Leaders from China and the European Union on Tuesday exchanged congratulatory messages over the 50th anniversary of the establishment of diplomatic ties between the two sides, as Beijing and Brussels fully resumed legislative exchanges.

In his message to European Council President Antonio Costa and European Commission President Ursula von der Leyen, President Xi Jinping described the two sides as "two major forces promoting multipolarization, two major markets supporting globalization and the two major civilizations advocating diversity".

Xi said he is ready to use the anniversary as an opportunity to review the experiences drawn from the development of ties, deepen strategic communication, enhance mutual understanding and trust, strengthen partnership, expand mutual openness, properly handle friction and differences, and work toward an even brighter future for China-EU ties.

China and the EU should adhere to multilateralism, defend fairness and justice, oppose unilateralism and bullying, and join hands to address global challenges, he said.

He added that they also should jointly build an equitable and orderly multipolar world and inclusive economic globalization, and make greater contributions to world peace, stability, development and prosperity.

Premier Li Qiang said in a separate message to the two EU leaders that Beijing is willing to "further enhance the stable, constructive, mutually beneficial and global nature of China-EU relations", and inject more stability and positive energy into the world.

The EU leaders said that over the past 50 years, the two sides have become each other's most important trade partners, contributing to the well-being of their people and to economic prosperity.

They also said that amid current global uncertainties and geopolitical changes, the EU is ready to deepen its partnership with China, strengthen interaction and cooperation, uphold the purposes and principles of the United Nations Charter, join hands to address common challenges, and promote world peace, security, prosperity and sustainable development, according to Xinhua News Agency.

Also on Tuesday, Foreign Ministry spokesman Lin Jian confirmed that China and the European Parliament have decided to simultaneously and comprehensively lift restrictions on mutual exchanges between the two sides' legislative bodies.

"We believe and expect that with the full resumption of contacts between the legislative bodies of China and Europe, the exchanges and understanding between the two sides will be deeper," he added.

Ding Chun, director of Shanghai-based Fudan University's Center for European Studies, said, "This is one of the best ways to mark the 50th anniversary of China-EU relations.

"I expect both sides to seek more common ground, phase out differences, steadily advance bilateral ties and, in particular, advance the improvement and finalization of the frozen China-EU Comprehensive Agreement on Investment," he added.

China and the EU have a combined economic output of more than one-third of the world's total output, and their two-way trade exceeds one-fourth of total world trade.

Annual bilateral trade has grown from $2.4 billion when the diplomatic ties were established to $785.8 billion last year.

Furthermore, the accumulated two-way investment has increased to $260 billion.

Cai Run, head of the Chinese mission to the EU, wrote in an article in People's Daily on Tuesday that both sides advocate safeguarding the world's multilateral trade system with the World Trade Organization at its core, and oppose unilateralism and hegemony, and both are committed to promoting the world's multipolarity and economic globalization.

Cui Hongjian, a professor of European studies at Beijing Foreign Studies University's Academy of Regional and Global Governance, said that China-EU ties over five decades have proved that the two sides "are two constructive forces in maintaining peace and promoting development".

"Mutual respect, moving toward each other and pragmatic cooperation can serve as a source of confidence and strength for the EU to cope with various changes in the current circumstances," he said.

The two sides' rich experience of continuously enhancing China-EU cooperation and managing competition over the past five decades "has helped build up resilience and mutual attraction in China-EU relations that cannot be curbed by the world's chaotic situation," he added.

Officials expect that a number of key agenda items will move forward between the two sides this year, including visits and meetings.

Lin, the Foreign Ministry spokesman, said that Beijing welcomes Costa and von der Leyen to jointly come to China for a new round of the China-EU leaders' meeting, adding that the two sides will also hold high-level dialogues on strategy, economy and trade, and the green and digital economy.