Senior North Korean Diplomat Choe Son Hui leaves the Ritz-Carlton hotel following a meeting in Singapore June 11, 2018 Reuters file

Talks held near the Swedish capital Stockholm that ended Monday and included representatives from North and South Korea and the United States were constructive, Sweden's foreign ministry said.

They were seen helping pave the way towards a second summit planned for next month between U.S. President Donald Trump and North Korean leader Kim Jong Un.

"Constructive talks have been held covering issues concerning developments on the Korean peninsula, including confidence building, economic development and long-term engagement," a ministry spokesman said.

Trump is due to meet Kim in late February but will maintain economic sanctions on Pyongyang, a White House spokeswoman said on Friday.

Pompeo talks North Korea with Tokyo and Seoul 2019-01-22 10:02  |  North Korea S. Korea playing mediating role in Sweden 2019-01-21 17:19  |  Politics South Korea is 'not bystander' in nuke talks: Moon 2019-01-21 16:52  |  Politics That announcement coincided with the visit to Washington of former North Korean spy chief Kim Yong Chol and hinted at movement in a denuclearisation effort that has stalled since a landmark first meeting between Trump and the North Korean leader last year.

A diplomatic source said the Swedish round-table conference, held on the outskirts of Stockholm over the weekend and concluded on Monday, had touched on the planned summit while bilateral talks had also been held on the sidelines.

"Different mechanisms for regional security have been discussed, that issue was something to which a lot of time was devoted," the source said.

North Korean Vice Foreign Minister Choe Son Hui, U.S. Special Representative for North Korea Stephen Biegun and South Korean negotiator Lee Do-hoon took part.

Sweden serves as "protecting power" in North Korea for the United States, which has no representation in Pyongyang, and also held talks with North Korean officials last year in the lead-up to the first Trump-Kim summit. (Reuters)