UN Secretary-General Antonio Guterres today welcomed the announcement of a planned summit between the United States and North Korea, saying the breakthrough showed "leadership and vision." Guterres has repeatedly called for talks to address the crisis over North Korea's nuclear and missile tests, which the UN chief has described as the most pressing global security threat. President Donald Trump agreed on Thursday to a first face-to-face meeting with North Korean leader Kim Jong Un, which could take place by the end of May. Guterres "is encouraged by the announcement of an agreement" to hold a summit meeting, said UN spokesman Stephane Dujarric. "He commends the leadership and vision of all concerned," he added. In December, Guterres dispatched his political chief, Jeffrey Feltman, to Pyongyang to urge North Korea to open a dialogue on ending the crisis. Feltman, however, was then told by Pyongyang that "now was not the time" for talks, even if the North Korean officials agreed it was important to avoid war. The UN Security Council has imposed tough economic sanctions aimed at choking off revenue to Pyongyang's military programs after Kim's regime carried out a sixth nuclear test and a series of advanced missile launches. China - Pyongyang's sole ally - and Russia argue that sanctions alone will not push North Korea to change course and have repeatedly called for stepping up diplomatic efforts to achieve a solution.