The United States objects to Beijing’s unilateral military steps in the South China Sea, and has increased the pace of US freedom of navigation operations in the disputed waterway, US National Security Advisor John Bolton said on Tuesday. He was speaking to reporters in Singapore on the sidelines of meetings this week between the 10-member Association of Southeast Asian Nations (ASEAN) and external partners, including the US and China. Bolton also said that US President Donald Trump was prepared to hold a second summit with North Korean leader Kim Jong-un. The statement came after the release of a report detailing undeclared missile sites in the North that had been undergoing maintenance, Reuters reports.