The Japanese government also lodged a “strong protest” with North Korea, saying its missile launches threaten the safety and peace of Japan, the region and the international community.
The launch is the latest in a series of weapons tests by the North, including the firing of multiple cruise missiles on Wednesday that Pyongyang said was aimed at practicing tactical nuclear attacks.
On Friday, North Korea said it had tested a new nuclear-capable underwater attack drone, as leader Kim Jong Un warned that joint military drills by South Korea and the US should stop.
The allies concluded their regular springtime exercises, called Freedom Shield 23, last week, but have other field training continuing, including amphibious landing drills involving a US amphibious assault ship.
Pyongyang has long bristled at the allies’ drills, saying they are preparation for an invasion of the North.
South Korea and the United States say the exercises are defensive.