On the morning of June 29, Trump, who was attending G20 summit in Osaka, Japan, tweeted, "If Chairman Kim of North Korea sees this, I would meet him at the Border/DMZ just to shake his hand and say Hello(?)!" Five hours later, North Korean Foreign Minister Ri Yong-ho asked the U.S. to issue a formal notice. On the evening of the same day, Ri Yong-ho met with Stephen Biegun, the U.S. State Department's Special Representative for North Korea, at Panmunjom, in preparation for the summit. During the South Korea–U.S. Summit, South Korean president Moon Jae-in announced that Trump would be meeting Kim during his visit at the DMZ. Moon predicted that a handshake between Trump and Kim at the DMZ would be a "milestone" for denuclearization efforts on the peninsula. Although the meeting was billed as a spontaneous or impromptu meeting, Kim and Trump had exchanged letters earlier in the month. Andrei Lankov of Kookmin University "said it was inconceivable that the leaders of two powerful nations had arranged a meeting at such short notice. He described it as a 'show' designed to send a political message without raising expectations about actual progress." Following the conclusions of the 2019 G20 Osaka summit in Japan, on June 30, 2019, Trump and South Korean president Moon Jae-in visited the DMZ before the meeting with North Korean leader Kim Jong-un. Kim invited Trump to cross the border line, and Trump briefly crossed in North Korea before crossing back into South Korea together with Kim. Trump thus became the first U.S. president to enter North Korea. Before crossing into North Korea, Kim told Trump in Korean, "it's good to see you again" and "I never expected to meet you at this place", and shook hands with Trump. Trump said it was "my honor" to enter North Korea. During their meeting, Trump also invited Kim to the White House, although later acknowledged that this would probably not occur in the near term. Trump said of Kim: "A lot of really great things are happening, tremendous things. We met and we liked each other from Day One, and that was very important." Moon later joined Trump and Kim, and the three spoke for a brief moment before Kim and Trump held a 53-minute-long private meeting inside the Freedom House. Trump's top advisor Ivanka Trump, senior advisor Jared Kushner, Secretary of the Treasury Steven Mnuchin, and United States ambassador to South Korea Harry B. Harris, Jr., accompanied Trump to the DMZ.