South Korean President Lee Jae Myung arrived in Tokyo on Saturday for his first bilateral trip since taking office in June, opening a summit with Japanese Prime Minister Shigeru Ishiba at the prime minister’s residence. The leaders said closer Japan-South Korea ties are essential for regional security and agreed to reaffirm their three-way cooperation with the United States as North Korea’s missile programme and China’s influence grow. Ishiba called strong bilateral relations “crucial for regional stability,” while Lee said the two countries should step up cooperation given uncertainties in the global trade order. Negotiators are working on measures ranging from expanded working-holiday visas to joint efforts on semiconductor supply chains, according to Japanese and South Korean officials. The visit restarts the dormant “shuttle diplomacy” between the neighbours and comes in the 60th year of diplomatic normalisation. Lee will travel on to Washington for talks with U.S. President Donald Trump on Aug. 25, where burden-sharing for American troops and trade issues are expected to dominate the agenda.