This March 2, 2019 file photo shows Kim Yo-jong, sister of the Democratic People's Republic of Korea (DPRK)'s leader Kim Jong-un, attending a wreath-laying ceremony at Ho Chi Minh Mausoleum in Hanoi, Vietnam. (JORGE SILVA / POOL PHOTO VIA AP)

PYONGYANG - A regular 4 pm inter-Korean military hotline call from the Republic of Korea (ROK) went unanswered by the Democratic People's Republic of Korea (DPRK), ROK's Yonhap news agency reported on Tuesday.

The development came as the DPRK urged the US military to leave ROK, pledging to build up the DPRK's nuclear weapons in response to the upcoming joint US-ROK military drills.

Kim Yo-jong, vice department director of the Central Committee of the Workers' Party of Korea of the DPRK, said in a statement released by the Korean Central News Agency (KCNA) that the United States and ROK desperately started joint military exercises, further accelerating the unstable situation "despite the unanimous denunciation and rejection at home and abroad."

The joint United States-Republic of Korea military exercises include an "exercise of the staff for crisis control" on Aug 10-13 and a "combined command exercise" on Aug 16-26, according to the Korean Central News Agency

"They are the most vivid expression of the US hostile policy towards the DPRK, designed to stifle our state by force, and an unwelcoming act of self-destruction for which a dear price should be paid as they threaten the safety of our people and further imperil the situation on the Korean peninsula," said Kim, who is also the younger sister of the DPRK's top leader Kim Jong-un.

The ROK and the US on Tuesday began the four-day preliminary drill ahead of next week's annual military exercise, Yonhap news agency reported, citing unidentified military and government sources.

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The joint US-ROK military exercises include an "exercise of the staff for crisis control" on Aug 10-13 and a "combined command exercise" on Aug 16-26, according to the KCNA.

"The dangerous war exercises pushed ahead by the US and the South Korean side disregardful of our repeated warnings will surely make them face more serious security threat," she warned.

The ROK is also referred to as South Korea.

She urged the United States to withdraw its troops from ROK, saying "for peace to settle on the peninsula, it is imperative for the US to withdraw its aggression troops and war hardware deployed in South Korea.

As long as the US forces stay in ROK, "the root cause for the periodic aggravation of the situation on the Korean peninsula will never vanish," Kim said.

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With inputs from Agencies