The trips follow their two-day visit from last Monday to North Korea where the envoys held talks and a dinner with leader Kim Jong-un.

In his first-ever meeting with South Korean officials, the North Korean leader said his country was willing to denuclearize in exchange for a security guarantee, according to Chung.

Chung later told US President Donald Trump that Kim also wished to hold a North Korea-US summit.

Trump has agreed to meet the reclusive North Korean leader by May. The Trump-Kim meeting will likely follow what would be a third inter-Korean summit, scheduled to be held late next month.

"We have been able to reach an agreement for a South-North summit in late April, thanks to our people's support, and it appears a summit meeting between the United States and North Korea may be held as well," Chung told reporters shortly after returning from his US trip on Sunday.

"I wish to express my respect to President Moon Jae-in and President Trump and their firm determination to denuclearize the Korean Peninsula at an early date and establish peace," he added.

Chung was scheduled to brief the Chinese president on the outcome of his North Korea trip later in the day, according to officials from Seoul's presidential office Cheong Wa Dae.

He will head to Russia on Tuesday to do the same for that country's top decision-makers. Whether Russian President Vladimir Putin will meet the South Korean envoy remained unclear as less than a week remained before Russia's presidential election, slated for Sunday, Cheong Wa Dae officials said. (Yonhap)