Over a week after North Korea said it conducted its sixth nuclear test on Sept. 3, prompting the U.N. Security Council to step up sanctions with a ban on the reclusive regime’s textile exports and a cap on fuel supplies, South Korea said on Wednesday traces of radioactive xenon gas were confirmed to be from a North Korean nuclear test earlier this month, although it noted that it was unable to conclude whether the test had been a hydrogen bomb as Pyongyang claimed.

According to Reuters, South Korea's Nuclear Safety and Security Commission (NSSC) said its land-based xenon detector in the northeastern part of the country found traces of xenon-133 isotope on nine occasions, while its mobile equipment off the country’s east coast detected traces of the isotope four times.

“It was difficult to find out how powerful the nuclear test was with the amount of xenon detected, but we can say the xenon was from North Korea,” Choi Jongbae, executive commissioner, told a news conference in Seoul. The commission could not confirm what kind of nuclear test the North conducted, he added.

A US monitoring group also said on Wednesday that North Korea’s latest nuclear test had had a yield of 250 kilotons, which is much higher than earlier, official estimates. The authoritative US website 38 North, which is linked to the Johns Hopkins University, said that it was lifting its estimate for the yield of the blast to “roughly 250 kilotons.” The figure is more than 16 times the size of the 15-kiloton US bomb that destroyed the Japanese city of Hiroshima in 1945. Other official estimates of the yield vary from South Korea’s 50 kilotons to Japan’s 160.

The NSSC also said the xenon traces detected had no impact on South Korea’s environment and population. Xenon is a naturally occurring, colorless gas that is used in manufacturing of some sorts of lights. But the detected xenon-133 is a radioactive isotope that does not occur naturally and which has been linked to North Korea’s nuclear tests in the past.

Meanwhile, Seoul announced on Wednesday that it had conducted its first live-fire drill for an advanced air-launched cruise missile in a bid to strengthen the country’s pre-emptive strike capability against North Korea.

The Taurus missile launched from an F-15 jetfighter traveled through obstacles at low altitudes before striking a target off the South's western coast, the Defense Ministry said. The missile, manufactured by Germany's Taurus Systems, is reported to have a maximum range of 500 kilometers and its stealth characteristics allow it to avoid radar detection.

Meanwhile, North Korea, has remained defiant. As we will detail in a subsequent article, Kim's regime reacted to the “evil” sanctions by vowing on Wednesday to further step up its weapons programs.

“The adoption of another illegal and evil ‘resolution on sanctions’ piloted by the US served as an occasion for the DPRK (North Korea) to verify that the road it chose to go down was absolutely right,” said the North’s Foreign Ministry in a statement published by the state-run KCNA news agency.

“The DPRK will redouble the efforts to increase its strength to safeguard the country’s sovereignty and right to existence,” it added.

Earlier on Tuesday, President Donald Trump said on Tuesday that the new sanctions on the North were a small step. “I don’t know if it has any impact, but certainly it was nice to get a 15-to-nothing vote, but those sanctions are nothing compared to what ultimately will have to happen,” Trump said in vague but threatening remarks.

Which suggests that more Xenon will be detected soon, and the market's current state of cautious optimism on the recent N.Korean easing in tensions will be violated.