North Korean leader Kim Jong Un on Saturday invited South Korean President Moon Jae-in to the North as dialogue between the rival countries countinues during the 2018 Winter Olympics.

Kim’s special envoy, his sister Kim Yo Jong, delivered the verbal invitation during a lunch meeting with Moon at Seoul’s Blue House, spokesman Kim Eui-kyeom said.

The spokesman said Moon replied that the two countries should continue to work toward improving their relationship so a summit could take place.

He said Moon also called for the U.S. and North Korea to renew communications.

Moon has said he would be willing to visit Pyongyang to talk directly with Kim Jong Un about cooling off the country’s nuclear program.

North Korea last year conducted its sixth and most powerful nuclear test to date.

The Associated Press contributed to this report.