President Park Geun-hye, now on a four-day visit to China, had talks with her counterpart Xi Jinping on Thursday, which covered North Korea’s nuclear ambitions, regional security, bilateral economic ties and many other issues. Their agreements will undoubtedly serve as guidelines for South Korea’s relations with China during the next five years of her governance, if not longer.

Her selection of Beijing over Tokyo as her second destination for summit diplomacy after Washington speaks volumes about changing trilateral relations in Northeast Asia. China has brought itself closer to South Korea as a business partner. Holding more leverage on North Korea than any other country in the world, China is capable of contributing much more to peace on the Korean Peninsula than Japan.

Moreover, Japan has distanced itself from South Korea and China, with its leaders backtracking on Japan’s colonialist past. Prime Minister Shinzo Abe went so far as to claim that “invasion” had no firmly established definition, either internationally or academically. He said this when asked about Japan’s apology for invading Korea, China and other Asian countries.

South Korea’s worsening relations with Japan are revealed by their decision not to extend a bilateral currency swap agreement when it expires on July 3. In a battle of egos, South Korea refrained from asking for an extension of a won-yen currency swap arrangement equivalent to $3 billion, and Japan did not offer one.

In contrast, Park and Xi signed an agreement that permits a won-denominated amount equivalent to $56 billion to be swapped for the Chinese currency until October 2017. The two countries may expand the swap arrangement if deemed necessary.

But this is not to say South Korea and China have much to gain by promoting bilateral relations, be they economic or security, at the expense of Japan. On the contrary, Park regards Japan as a potential key partner in promoting her vision for peace and prosperity in Northeast Asia. In this regard, Park agreed with Xi to push to hold a trilateral summit, which had been scheduled for May only to be postponed indefinitely, by the end of this year.

In the Park-Xi talks, North Korea’s nuclear armament emerged as a key agenda item. Affirming that denuclearization on the Korean Peninsula would serve the common interests of South Korea and China, the two leaders agreed to make joint efforts in this regard. In other words, they were telling North Korea to scrap its nuclear weapons program.

China must now put pressure on North Korea to honor its Sept. 19, 2005, commitment to suspending its nuclear program, submitting its nuclear facilities to international inspections and returning to the treaty on the nonproliferation of nuclear weapons. If necessary, it will have to twist North Korea’s arm. China also needs to pressure North Korea to comply with the U.N. resolutions against its nuclear tests.