SEOUL/WASHINGTON — The top diplomats of South Korea and the United States have agreed to continue "close" communication and cooperation to address North Korea's nuclear issue and promote peace on the Korean Peninsula during a call, Seoul's foreign ministry said Tuesday. Foreign Minister Cho Hyun and U.S. Secretary of State Marco Rubio held phone talks on Monday (Seoul time), as U.S. President Donald Trump recently declined to answer a question over whether his goal in reengaging with North Korean leader Kim Jong-un is denuclearization, spawning concerns that the United States could acknowledge the North as a nuclear-armed state. "The minister and secretary agreed to continue close communication and cooperation between South Korea and the U.S. for peace on the Korean Peninsula and the resolution of North Korea's nuclear issue while maintaining a solid combined defense posture," the ministry said in a press release. In particular, Cho said that the Seoul government will do its best to help ensure that Trump's recent message for North Korea will lead to the resumption of dialogue between