U.S. ambassador to the UN urges North Korea to "sit at the negotiating table" Linda Thomas-Greenfield arrived in South Korea on Sunday with the aim of maintaining pressure on nuclear-armed North Korea.

Visit comes after a Russian veto in the Security Council in late March led to the dissolution of the UN sanctions monitoring system against Pyongyang. In September, Russian President Vladimir Putin and North Korean leader Kim Jong-un held a summit in the Russian Far East, during which Kim said ties with Moscow were the "number one priority" from his country. In early March, South Korea said North Korea had shipped about 7,000 containers of weapons to Russia for its war against Ukraine since transfers began in July. The United States and South Korea condemned Moscow's veto as an  "irresponsible"   ‘We strongly ask Russia and China to reverse course and once again urge Pyongyang to choose diplomacy and sit down at the negotiations table,’ insisted Ms. Thomas- greenfield.