North Korea believes there is a "strong possibility" of a second summit between the country's leader Kim Jong Un and US President Donald Trump, CNN reported quoting an official with close knowledge of Pyongyang's position on the matter.

The official pointed to a recent exchange of letters between Trump and Kim as a positive sign, adding that although the date and location of the summit have yet to be determined, it would take place "sometime later this year."

As it was reported earlier, North Korean FM Ri Yong Ho called America's actions since the June 12 Singapore summit "alarming," highlighting economic sanctions and a lack of a Korean War peace treaty as major issues that could derail the nuclear talks.

The official said the latest North Korean statements were a "negotiating tactic to put pressure" on the Trump administration ahead of US midterm elections. North Korea hopes that Trump and Kim will negotiate denuclearization terms that are more favorable to Pyongyang, the official added.

South Korea's Presidential Spokesperson Kim Eui-keum said on Monday the South is "asking North Korea to speed up its denuclearization" and asking the US to "show sincere efforts about corresponding measures that North Korea is demanding."