SINGAPORE - North Koreans' diligence and discipline have "left a deep impression" on Dr Tan Wu Meng, Senior Parliamentary Secretary for Foreign Affairs and Trade and Industry, who represented Singapore to attend events related to the 70th anniversary of the founding of North Korea.

"What left a deep impression was the diligence and discipline of the DPRK people, which was particularly evident from the organisation and choreography of the official Parade and the separate Mass Gymnastics and Artistic Performance, involving tens of thousands of people," Dr Tan said in a Facebook post on Tuesday (Sept 11) night, referring to North Korea by its official name the Democratic People's Republic of Korea.

He visited North Korea from Sept 8 to 10 at the invitation of Pyongyang, and also met the North's Vice-Foreign Minister Choe Hui Chol.

"There is certainly potential for the DPRK to achieve more in an environment of peace," Dr Tan said.

"We hope that all parties involved will continue to make progress towards lasting peace and stability on the Korean Peninsula," said Dr Tan, who was accompanied by officials from the Ministry of Foreign Affairs on the trip.

The White House said on Monday that US President Donald Trump had received a "very positive" letter from North Korean leader Kim Jong Un seeking a follow-up meeting after they held a historic summit in Singapore in June.

The White House said it was "open" to a new summit with Mr Kim, chairman of the North's State Affairs Commission.