North Korea has fired another missile towards the Sea of Japan (Korean: East Sea).
This was reported by the South Korean news agency Yonhap, citing the military.
"North Korea has launched a suspected ballistic missile," the Japanese prime minister's office said in a tweet.
On Tuesday, Pyongyang sent a medium-range ballistic missile toward the Sea of Japan.
It was the first time a North Korean missile had flown over the Japanese archipelago in almost five years.
The United States and South Korea then fired missiles in the region themselves on Wednesday.
South Korea's military said the US and South Korea fired four surface-to-surface missiles toward the Sea of Japan in response to North Korea's provocation.
This demonstrated the Allies' ability to deter further provocations.