A flurry of activity was spotted on Tuesday morning at Pyongyang’s Sunan International Airport before the arrival of South Korean President Moon Jae-in.

Images of the airport transmitted live showed thousands of North Korean citizens standing by at from 9:20 a.m., waving both North Korean and the unified Korean flags.

It marked the first time for citizens to hold the unified Korean flag at an inter-Korean summit.

Kim Yo-jong, the younger sister of North Korean leader Kim Jong-un, was seen leading final preparations for Moon’s welcoming ceremony.

Behind the crowd at the airport, the North set up a placard which read “Let’s usher in an era of peace and prosperity with the Korean people’s united efforts.”

Another placard read “We warmly welcome President Moon Jae-in to Pyongyang.”