US Secretary of State Mike Pompeo said on Tuesday that the working-level talks between Washington and Pyongyang did not resume as quickly as they expected, as there are "bumps along the way."

"We haven't gotten back to the table as quickly as we would have hoped," said Pompeo in an interview with CBS on Tuesday.

"We know there'll be bumps along the way," the top US diplomat added.

Tension on the Korean Peninsula has risen recently amid Pyongyang's short-range projectile launch on Friday, the sixth of its kind in the past three weeks and seen as a protest against the US-South Korean military drills.

When asked if Pyongyang's short-range projectile launch concerned him, Pompeo said that "I wish that they would not."

Currently, US Special Representative for the Democratic People's Republic of Korea (DPRK) Stephen Biegun is undergoing his four-day tour in Japan and South Korea, meeting with officials there to discuss the denuclearization on the Korean Peninsula.

At the end of June, US President Donald Trump and DPRK top leader Kim Jong Un met at the inter-Korean border, and the two leaders agreed to set up teams to resume the working-level negotiation in weeks. But the negotiation has not taken place yet.

Pompeo told media earlier this month that he was hopeful that Washington and Pyongyang would get back to the negotiating table in the coming weeks.