A senior U.S. official said the United States is aware of reports of North Korea's projectile launches and is monitoring the situation with its allies in the region.

South Korea's Joint Chiefs of Staff said North Korea fired three projectiles Monday morning toward the East Sea from areas near its eastern town of Sondok in South Hamgyong Province. The projectiles reportedly flew up to 190 to 200 kilometers. 

The U.S. official told Yonhap News that Washington is aware of reports of the launches.

The U.S. has responded similarly to previous such actions by North Korea.

Last week, U.S. President Donald Trump said he had "no reaction" to North Korea's previous projectile launches, calling them "short-range missiles."