US Secretary of State Mike Pompeo said on Sunday that his talks in the Democratic People's Republic of Korea (DPRK) were "productive".

The top US diplomat made the remarks during his meeting with the Republic of Korea (ROK) President Moon Jae-in in Seoul after visiting Pyongyang earlier in the day, according to ROK's Blue House. 

Pompeo met with top DPRK leader Kim Jong Un for two hours, the two had lunch together, then he flew to Seoul to share the outcome of their meeting with Moon and ROK Foreign Minister Kang Kyung-wha, Yonhap News Agency reported.

Pompeo told Moon that it was very important for him to travel to Seoul right after visiting the DPRK as it indicated ROK having a very important role in denuclearizing the Korean Peninsula. 

He said his visit to the DPRK was very good and he had productive talks, noting that the two countries walked another step forward though there are lots of things left to do. 

ROK's presidential office said on Sunday that Kim and Pompeo agreed to arrange a second summit between the two countries as soon as possible, Reuters reported.

Moon's press secretary Yoon Young-chan said that Pompeo and Kim also agreed to form a working group to discuss the denuclearization process and the second summit between Kim and US President Donald Trump.  

The ROK president expressed his hope that Pompeo's visit to the DPRK and the upcoming second summit between the US president and the DPRK leader become an opportunity to make an irreversible, decisive progress in the denuclearization and peace process on the Peninsula. 

Pompeo's fourth trip to the DPRK comes after Kim's reaffirmation of his resolve to denuclearize during his third summit with Moon in Pyongyang last month, according to Yonhap News Agency.

Trump and Kim were forecast to hold their second summit in the near future, after having the first-ever DPRK-US summit in Singapore on June 12. 

During the third summit in Pyongyang, last month between Moon and Kim, the leaders of the two Koreas agreed to denuclearize the Peninsula and stop hostile acts along the heavily-fortified border.

(Cover photo: US Secretary of State Mike Pompeo talks with ROK President Moon Jae-in during their meeting in Seoul, October 7, 2018. /Reuters Photo)

(With inputs from Xinhua News Agency and Reuters)