A South Korean court on Tuesday approved an arrest warrant for President Yoon Suk Yeol, who has been impeached and suspended from power over his decision to impose martial law on December 3, investigating authorities said. In another development, US officials have said that a Chinese state-sponsored hacker has broken into the US Treasury Department's systems, accessing employee workstations and some unclassified documents. The breach occurred in early December and was made public in a letter penned by the Treasury Department to lawmakers notifying them of the incident. Watch NDTV'S The World Report for the latest updates.