North Korea vows to put spy satellite in orbit soon after failed launch

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

The remarks by Kim, a powerful ruling party official, came a day after a failed attempt at launching the country's first spy satellite, which plunged into sea.

Kim rejected condemnation of the launch by Washington and other countries as an infringement of its sovereign right to space development.

"It is certain that (North Korea's) military reconnaissance satellite will be correctly put on space orbit in the near future and start its mission," Kim said in an English-language statement carried by KCNA.

Soon after the launch vehicle failed, South Korea detected debris that splashed down off its west coast and began a salvage operation in the hopes of studying the new rocket.

"The part we found appears to be the second stage of the rocket," South Korea's Defence Minister Lee Jong-sup told parliament on Thursday. "We are continuing search operations to find more, including the third stage and the payload.

"A large and heavy object remains submerged, and will require time and specialised equipment to raise it."

It was not clear when the North might try another launch. It may take weeks or more to resolve the problems that caused the rocket's failure, a South Korean lawmaker said on Wednesday, citing the South's intelligence agency.

In a rare and swift admission of the setback, KCNA reported just hours after the launch that the Chollima-1 rocket, carrying a military reconnaissance satellite known as "Malligyong-1", crashed into the sea after the second stage engine failed.

KCNA also published on Thursday images of what it said was the new rocket lifting off from a coastal launch pad. The white-and-gray rocket had a bulbous nose, apparently for carrying a satellite or other cargo.

The photos confirmed that the rocket is a new design, said Ankit Panda of the US-based Carnegie Endowment for International Peace.

"The launch used the new coastal launch pad they've built at Tongchang-ri, so we might see a larger space launch vehicle use the traditional gantry that has seen some work recently," he added.

US-based monitors, including 38 North and the Center for Strategic and International Studies, reported that commercial satellite imagery showed significant activity at the main pad after Wednesday's launch.

South Korea's Joint Chiefs of Staff said it could be presumed from North Korea's state media photos that the rocket was launched from a new pad.

Wednesday's launch was widely criticised, including by South Korea, Japan and the United States.

Speaking in Tokyo, US Defence Secretary Lloyd Austin said, "North Korea's dangerous and destabilising nuclear and missile programs threaten peace and stability in the region."

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

In her statement, Kim Yo Jong said the criticisms of the launch were "self-contradiction" as the US 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 criticised US-led military drills in the region including a multinational anti-proliferation naval drill.