The sister of North Korean leader Kim Jong-un warned Sunday that annual summertime military drills between South Korea and the United States will cloud the future of inter-Korean relations.

Kim Yo-Jong issued the warning in a statement carried by the Korean Central News Agency, just days after the North restored long-severed communication lines with the South and raised hope for a new round of detente between the two sides.

"I surely see the military drill, which takes place at an important turning point like this, will become an unpleasant prelude to seriously hurting the will of the leaders of the North and South seeking to take the step toward rebuilding trust again and further clouding the path lying ahead for inter-Korean relations," Kim said.

"Our government and military will closely watch whether South Korea will carry out their hostile war exercise once again or make a bold decision," she added. "Hope or despair? The decision is not upon us."  

On Tuesday, the North restored communication lines with South Korea more than a year after cutting them off in protest of anti-Pyongyang leaflets sent from the South. The surprise move raised hope for the resumption of long-stalled cross-border dialogue, including the possibility of summit talks.

Kim, however, cautioned against reading too much into the restoration, saying that it would be a "premature, careless judgment" to talk about an inter-Korean summit just because the communication lines were restored.

"I think the restoration of communication lines is nothing but physical reconnection of what had been severed. No more meaning than that should be attached to it," she said. "Hasty speculation and groundless interpretation could bring about only disappointment."

South Korea and the US are expected to hold the annual summertime joint military exercise in August, though Seoul's defense ministry earlier said that the allies are discussing when and how to stage the exercise.

North Korea has long denounced Seoul and Washington's military drills as a rehearsal for an invasion of the North. The allies say that the exercises are defensive in nature.

On Friday, a high-ranking unification ministry official in Seoul told reporters that it is "desirable" for South Korea and the US to suspend their summertime military exercise, citing the global coronavirus pandemic and the need to engage North Korea. (Yonhap)