After leaving St. Regis Hotel at 9:10 p.m., Kim visited the city-state's tourist attractions, including Gardens by the Bay and the Marina Bay Sands integrated resorts.
The Straits Times posted a photo in which Kim posed with Singapore's Foreign Minister Vivian Balakrishnan.
Kim was also expected to visit the MBS SkyPark or the nearby Merlion Park, it added.
Kim arrived in the Southeast Asian state on Sunday for the historic encounter with Trump at the Capella Hotel on Sentosa Island on Tuesday.
Except for talks with Singapore's Prime Minister Lee Hsien Loong on Sunday evening, Kim had not stepped out of St Regis hotel.