US President Donald Trump said on Monday that his country has had "positive correspondence" with the Democratic People's Republic of Korea (DPRK) recently.

"There was a little correspondence recently ... very positive correspondence with North Korea (the DPRK)," Trump told reporters at the White House ahead of his meeting with Pakistani Prime Minister Imran Khan.

Meanwhile, Trump shunned away from giving a specific timetable about when the two sides will resume talks on the Korean peninsula denuclearization, only saying that it will happen "when they are ready."

Earlier on Monday, US Secretary of State Mike Pompeo also told the media that Washington kept in contact with Pyongyang.

"The State Department has had a number of conversations with the North Koreans," Pompeo said in an interview with Fox & Friends.

Pyongyang and Washington were expected to resume working-level talks in mid-July following a DPRK-US leaders' meeting at Panmunjom last month.

However, the DPRK said on Tuesday that Pyongyang might end the scheduled working-level negotiations with Washington if a planned joint military exercise between the United States and South Korea happens.