SEOUL, June 8 (Reuters) - South Korea pledged support for its chip sector on Thursday, with President Yoon Suk Yeol describing competition in the industry as an "all-out war" amid heightened U.S.-China tensions. Earlier in the day, Yoon met with about 60 industry leaders, lawmakers and ministers to discuss how to maintain South Korea's lead in memory chips, foster development of system semiconductors, and secure materials, equipment and labour. "Geopolitical issues have become the biggest risk for companies to manage as of late. Companies alone cannot resolve this problem - it is one that the nation should tackle by strengthening...