Sauce about the summit being cancelled from Asian news sources:
Donald Trump calls off Singapore summit with North Korea
https://www.channelnewsasia.com/news/donald-trump-calls-off-kim-jong-un-north-korea-summit-singapore-10275300
Singapore says regrets cancellation of summit between United States and North Korea
https://www.channelnewsasia.com/news/singapore/singapore-regrets-trump-kim-summit-cancelled-10275664