China said Tuesday that it hopes all parties can narrow their differences through dialogue and consultations, resolve their respective legitimate concerns, and continue to advance the denuclearization and the process of building a peace mechanism on the Korean Peninsula, Foreign Ministry spokesperson Hua Chunying told a daily news briefing.

North Korea on Tuesday fired projectiles into the sea, South Korea's military said, hours after Pyongyang said it was willing to hold working-level talks this month with the US.

Negotiations between Pyongyang and Washington have been gridlocked since a second summit between the North's leader Kim Jong-un and US President Donald Trump in February ended without a deal.

North Korea twice launched "unidentified projectiles" on Tuesday morning in an easterly direction. The objects flew approximately 330 kilometers from the Kaechon area in South Pyongan province, according to the South Korean military.

"We urge the North to stop such acts that escalate tensions in the region," South Korea's Joint Chiefs of Staff said in a statement.

No further details were immediately available but it was the latest in a series of provocations. 

Previous launches have been identified as short-range missiles.

"We are aware of reports of projectiles launched from North Korea," a senior US official said. "We are continuing to monitor the situation and consulting closely with our allies in the region."

Trump and Kim had agreed to restart working-level dialogue during an impromptu meeting at the Demilitarized Zone dividing the North and South ­Korea in June, but those talks have yet to begin.

"We have willingness to sit with the US side for comprehensive discussions of the issues we have so far taken up at the time and place to be agreed late in September," Choe Son-hui, the North's vice foreign minister, said in a statement carried on Monday by the official Korean Central News Agency.

Choe's comment followed her warning in late August that North Korea's "expectations of dialogue with the US are gradually disappearing," after Pyongyang conducted a series of weapons tests to protest joint US-South Korean military exercises.