US President Donald Trump arrived in Singapore on Sunday amid great optimism about Tuesday's summit with Democratic People's Republic of Korea top leader Kim Jong-un on improving ties and ultimately achieving the denuclearization of the Korean Peninsula.

Trump's Air Force One landed at Singapore's Paya Lebar Air Base on Sunday evening about six hours after Kim's arrival at Changi Airport.

"We have to get denuclearization. We have to get something going," Trump told the media shortly before departing for Singapore from Charlevoix, Canada, where he attended the G7 summit and clashed with leaders of the six other nations over additional US steel and aluminum tariffs.

He said, "We appreciate everything that's going on", adding "we appreciate working together" with the DPRK. "They're really working very well with us."

The optimism and confidence is a big contrast to just months ago when Trump and Kim engaged in a war of words, including trading personal insults. On May 24, Trump abruptly canceled the June 12 summit, but revived it eight days later. Tuesday's summit will be the first meeting between a sitting US president and a top DPRK leader.