State Councilor Yang Jiechi told Japan's National Security Advisor Shotaro Yachi that Japan should "play a constructive role" in the success of the upcoming G20 Leaders Summit in China.

Yang made the comments when co-hosting the third China-Japan High-level Political Dialogue in Beijing on Thursday.

Yachi is a key advisor to Japanese Prime Minister Shinzo Abe, and the first and second dialogue were held last year.

The summit is scheduled on September 4-5 in eastern China's Hangzhou city.

As China and Japan are respectively the second and third largest global economies, their cooperation in ensuring the success of the summit "serves the common interest of all parties", Yang said.

On the bilateral relationship, Yang said currently the process of its improvement is "still disturbed by various issues", and particularly maritime issues have taken a higher profile recently.

"This does not serve bilateral interests," Yang said, adding that Japan should match its words with actions and tangibly fulfill positive and friendly policies toward China.

Japan, it is hoped, will make more "pluses" when it comes to cooperation and achieving win-win situations, and less "minuses" when it comes to contradictions and divergences, Yang said.

As next year marks the 45th anniversary of China and Japan normalizing their diplomatic ties, Yang said the two sides are expected to take the opportunity to further uphold the four bilateral political documents and their four-point principled consensus.

Both sides should maintain political and diplomatic contacts, cautiously and appropriately tackle major issues, reinforce pragmatic exchanges and cooperation and create an enabling atmosphere of public opinion to achieve the steady progress of China-Japan ties, Yang added.

Yachi said Japan hopes to consistently improve and develop ties with China, it values the great significance of the four key documents and four-point principled consensus.

Japan is ready to boost communication with China, strengthen mutual trust, appropriately tackle issues facing the two-way ties, and reinforce pragmatic cooperation in fields including finance and environmental protection.

Tokyo supports China's hosting the G20 summit in Hangzhou, Yachi added.