North Korea’s failed satellite was not capable of conducting military reconnaissance from space, South Korea’s military said after studying retrieved wreckage.

The long-range rocket, which North Korea said was party of a space-based intelligence system, plunged into the sea off the Korean Peninsula’s west coast after launching in May.

South Korea’s Joint chiefs of staff said debris had been recovered in a 36-day operation with “numerous” and “key” parts of the satellite salvaged by navy ships, aircraft and drivers.

Experts from South Korea and the US said on Wednesday that after examining the debris, the satellite was not capable of military reconnaissance.

North Korea, which at the time of the launch said the rocket had lost thrust, did not respond to the announcement.

At a ruling party meeting last month, North Korea called the failed launch “the most serious” shortcoming this year and harshly criticized those responsible.

Officials have repeatedly vowed to attempt a second launch after learning what went wrong with the failed launch.

North Korean leader Kim Jong Un has said acquiring a military spy satellite is crucial to beef up his country’s defence capability alongside other high-tech weapons systems such as multi-warhead nuclear missiles, solid-fuelled intercontinental ballistic missiles and nuclear-powered submarines.

Months before its failed satellite launch, North Korea launched a test satellite and publicised photos showing South Korean cities as viewed from space.

Some civilian experts said at the time the photos were too crude for a surveillance purpose and they were likely capable of only recognising big targets like warships at sea or military installations on the ground.

North Korea had responded by saying there was no reason to use a sophisticated camera for one test.

The US, South Korea and others denounced North Korea’s rocket launch as a security risk and a violation of UN Security Council resolutions banning the country’s use of ballistic missile technology.

Further sanctions are unlikely since permanent council members Russia and China oppose new action.