"We have seen the reports of a test, and are coordinating closely with our Korean and Japanese allies," the spokesperson said in a statement.
North Korea’s state media has earlier reported that the late Friday test was crucial for bolstering the country’s strategic nuclear deterrent.
The North Korean state news agency KCNA said that data collected during this and other recent experiments would be used for the development of a strategic weapon which would help overpower the US in case of an acute confrontation.
According to the outlet, the North Korean Academy of the National Defence Science announced on 8 December that it had conducted a “very important” test at the Sohae Satellite Launching Ground, which might reportedly be a test of a solid-fuel engine for intercontinental ballistic missiles.
Earlier, North Korea said the US "has nothing to offer us even if the talks are resumed," according to the Korean Central News Agency (KCNA).
Last week, North Korea's ambassador to the UN said that denuclearisation was off the table in talks with the US. This prompted US President Donald Trump to urge North Korea to denuclearise in accordance with the previously made agreement.