Kim Jong Un had said he is ready to meet Trump again for the denuclearisation of Korean Peninsula. (FILE)

North Korean leader Kim Jong Un's trip to China this week is a sign that a second summit between Kim and US President Donald Trump is "imminent", the South's President Moon Jae-in said Thursday.

"I think Chairman Kim Jong Un's visit to China will have a very positive effect on the success of the second US-North Korea summit," Moon told reporters.