It said Trump would leave at 8:00pm local time Tuesday for the United States, a day earlier than expected, allowing around 11 hours for the unprecedented tete-a-tete.

"The discussions between the United States and North Korea are ongoing and have moved more quickly than expected," a statement said.

"President Donald J. Trump will meet with North Korean leader Kim Jong Un tomorrow morning at 9:00am," it added.

"Following the initial greeting, President Trump and Chairman Kim will participate in a one-on-one meeting, with translators only, an expanded bilateral meeting, and a working lunch."