The Democratic People's Republic of Korea (DPRK) fired two cruise missiles toward the western waters, Yonhap news agency reported, citing a military official in Seoul.

The military authorities of the Republic of Korea and the United States were reportedly assessing the details of the missiles.

It was the second DPRK launch of cruise missiles this year since January and is not in violation of UN Security Council resolutions, which ban the DPRK from firing ballistic missiles.

Unlike ballistic missiles, cruise missiles are propelled by jet engines and stay closer to the ground, making them harder to detect. Most cruise missiles are not designed to carry nuclear warheads.

The missile test-firing came a day after the combined forces of the ROK and the U.S. kicked off their four-day preliminary drills ahead of the Ulchi Freedom Shield (UFS) exercise, a newly named summertime military exercise between the two allies involving field maneuvers.

The DPRK has denounced the exercise as a dress rehearsal for a northward invasion.