Kim Yo Jong, sister of North Korea's leader Kim Jong Un attends wreath laying ceremony at Ho Chi Minh Mausoleum in Hanoi
Kim Yo Jong, sister of North Korea's leader Kim Jong Un attends wreath-laying ceremony at Ho Chi Minh Mausoleum in Hanoi, Vietnam March 2, 2019. Reuters

North Korea's Kim Yo Jong, leader Kim Jong Un's sister, has said her country's military spy satellite will soon enter into orbit and promised Pyongyang will increase military surveillance, state media KCNA reported on Thursday.

"We are ready to act whatever it may be in defending its sovereign right and interests," Kim, a powerful government official in her own right, said in a statement carried by KCNA.

Her remarks follow the failure of a North Korean satellite launch on Wednesday.

The launch appeared to have been rushed and may need several weeks at least to fix its rocket's problem, a South Korean lawmaker said on Wednesday citing the South's intelligence agency.

In a rare admission of failure by North Korea, KCNA reported that a rocket carrying a military reconnaissance satellite known as "Malligyong-1" crashed into the sea after an accident occurred.

KCNA also published on Thursday images of what it said was the new Chollima-1 rocket lifting off with flames and smoke from a coastal launch pad. The white-and-gray rocket had a bulbous nose, apparently for carrying its satellite payload.

The launch was widely criticized including by South Korea, Japan and the United States.

U.N. Secretary-General Antonio Guterres said any launch by Pyongyang using ballistic missile technology breaches Security Council resolutions, a spokesperson said.

In her statement, Kim said the criticisms of Wednesday's test were "self-contradiction" as the U.S. and other countries have already launched "thousands of satellites."

In a separate statement carried by KCNA, North Korea's vice foreign minister Kim Son Gyong criticized U.S.-led military drills in the region including a multinational anti-proliferation naval drill.

Commercial satellite imagery of one of the launch pads at the Sohae Satellite Launching Station showed more than a dozen vehicles, U.S.-based 38 North, a program that analyzes North Korea, said in a report.

"Which pad was used for the launch cannot yet be confirmed," the report said. "However, activity at the main launch pad is consistent with post-launch assessment and clean-up efforts."