SEOUL (Reuters) – The recent attendance of four Asia-Pacific leaders at a NATO summit reflects a “consequential shift” in the U.S. transatlantic security partnership, which Washington is seeking to expand to better counter China, a senior U.S. official said diplomat at Reuters. In an interview in Seoul, Derek Chollet, a US State Department adviser who serves as a senior policy adviser to Secretary Antony Blinken, said he sees “great potential” for cooperation between South Korea and NATO, building on past exchanges. including global efforts to help Ukraine and European countries participating in the RIMPAC military exercises in Asia. “I think one of the most consequential changes we’ve seen over the decade is the growing relationship between our transatlantic partners and our partners here in the Indo-Pacific,” said Chollet. Last month, Yoon Suk-yeol became the first South Korean president to attend a NATO summit in Spain as he looks to play a bigger global role and forge European partnerships in the face of North Korea’s evolving nuclear threats. The participation of Yoon and the leaders of Japan, Australia and New Zealand, as well as NATO’s new strategic strategy listing China as a concern for the first time, was “truly historic” and “the beginning of a very close partnership,” Sole said. “I vividly remember a decade ago trying to talk to European allies about the importance of the Indo-Pacific and finding it difficult to get them to pay much attention. This has changed radically,” he said. “The foundation or principle of our approach to China is … alignment with partners and allies.” Sole also expressed hopes for stronger trilateral security cooperation between the United States, South Korea and Japan despite strained relations between Seoul and Tokyo over their wartime history. The death of former Japanese Prime Minister Shinzo Abe was a “terrible tragedy” and “horrific murder”, but his legacy and vision for the Indo-Pacific could provide an opportunity to further boost tripartite efforts, he said. The story continues “There’s a lot we can do together, whether it’s military exercises or cooperation on issues like global health,” Sole said. “We firmly believe that it is in our interest and in the interest of Japan and Korea that the two countries have strong ties,” he added, pledging to help both sides resolve the differences if necessary. (Reporting by Hyonhee Shin; Editing by Simon Cameron-Moore)