SAN FRANCISCO — President Lee Jae Myung wrapped up a two-day visit to San Francisco aimed at promoting artificial intelligence (AI) cooperation on Saturday and departed for Brazil as part of a three-nation South America tour for summits with regional leaders. During his visit to San Francisco on Friday and Saturday, the Korean president met with the chiefs of four global tech giants, including OpenAI Chief Executive Officer Sam Altman and Nvidia Corp. CEO Jensen Huang, calling for closer partnerships with Korean firms in AI. At a separate high-level meeting attended by Lee, global tech giants and Korean tech conglomerates agreed to pursue a series of cooperation projects worth a combined $950 billion. The projects include a long-term deal under which SK Group will supply $750 billion worth of high-performance semiconductors to Nvidia and others. As part of the South America tour, Lee will first pay a four-day state visit to Brazil from Sunday, which will include a summit with Brazilian President Luiz Inacio Lula da Silva in the capital, Brasilia, on Monday, followed by a business round