WASHINGTON -- The United States and South Korea remain ready to engage North Korea even as tensions have escalated over its threats against the South, a US official said Tuesday.

Marc Knapper, deputy assistant secretary of state for Korea and Japan, said the allies want to see a return to the spirit of the June 2018 Singapore summit where US President Donald Trump and North Korean leader Kim Jong-un agreed to work toward complete denuclearization and permanent peace on the Korean Peninsula.

"We're really unified in our view that the door to diplomacy remains open," he said during a virtual seminar hosted by the nonprofit Asia Society based in New York.

"We remain ready to engage in dialogue with the North, and we remain committed to a diplomatic solution to address the nuclear and missile issues. And we have to work hand in hand with the South Koreans to do this," he said.

His comments come as denuclearization negotiations have stalled and North Korea has threatened to take military action against the South. Shortly before Knapper spoke, the North said Kim had suspended the military action plans.

Knapper did not rule out the possibility of resuming US-North Korea diplomacy before the November presidential election in the US, saying that in the election year 2000, the late North Korean Vice Marshal Jo Myong-rok visited Washington in October and met with then US President Bill Clinton.

"History has shown the North Koreans seem quite capable of engaging in an election year, but again, I hesitate to sort of get much beyond that," he said. "I've been proven wrong before when it comes to making predictions about what's going to happen."

On the defense cost-sharing negotiations between Seoul and Washington, Knapper said it has been a "frustrating experience" to not have a renewed agreement six months after the previous one lapsed, but he projected confidence that the two sides will resolve their differences. (Yonhap)