Although South Korea and Japan typically issue alerts when North Korea launches missiles, they did not do so Thursday, raising the question of whether they detected the cruise missile exercise.

Later Friday, South Korea's military disputed North Korea's claim about the cruise missiles, without specifying what portion it believed was inaccurate.

"There is a difference between what South Korea-U.S. reconnaissance surveillance assets identified and what North Korea announced,” read a statement from South Korea’s Joint Chiefs of Staff.

“We are closely analyzing related matters in cooperation with the United States,” the statement added.

Cruise missiles typically fly at lower altitudes than ballistic missiles and are therefore harder for other countries to track and potentially intercept.

North Korea claims its cruise missiles are nuclear-capable. However, it is not clear whether it has built warheads small enough to be carried on such missiles.

Thursday's cruise missile launch comes days after North Korea tested an intercontinental ballistic missile — its ninth ICBM launch since the beginning of last year.

Even as it bolsters its defenses, North Korea has expressed outrage at the United States and its regional allies for expanding their own military activity.

In a statement Friday in KCNA, a North Korean Foreign Affairs Ministry official said the only way to prevent a “vicious cycle of escalating military tension” is for the United States to halt its military drills and deployment of advanced weaponry to the peninsula.

“The U.S. should bear in mind that if it persists in its hostile and provocative practices against the DPRK despite the latter's repeated protest and warning, it can be regarded as a declaration of war against the DPRK,” said Kwon Jong Gun, the director general of the ministry’s U.S. Affairs Department.

On Thursday, the United States and South Korea announced they held a tabletop exercise at the Pentagon that focused on the possibility of North Korea using a nuclear weapon.

The drill was followed by a visit to a U.S. Navy base in the southeastern U.S. state of Georgia where key U.S. nuclear submarines are based, according to a joint statement.

The discussion-based exercise, known as a TTX, was meant to assure South Korean leaders of the U.S. defense commitment amid North Korea's rapid nuclear weapons buildup.

"Given the DPRK's recent aggressive nuclear policy and advancements in nuclear capabilities, the TTX scenario focused on the possibility of the DPRK's use of nuclear weapons," the joint statement said.

The U.S. side reaffirmed that "any nuclear attack by North Korea against the United States or its Allies and partners is unacceptable and will result in the end of that regime."

Washington also vowed to "continue to field flexible nuclear forces suited to deterring regional nuclear conflict, including the capability to forward deploy strategic bombers, dual-capable fighter aircraft and nuclear weapons to the region."

The United States and South Korea are discussing the possible deployment of a U.S. nuclear-powered aircraft carrier to South Korea next month, the Yonhap news agency reported Friday.

If agreed, the carrier would make a port call in South Korea and participate in the allies’ upcoming Freedom Shield joint military drill, Yonhap reported.

On Wednesday, U.S., South Korean, and Japanese warships participated in a ballistic missile defense drill, a relatively rare display of trilateral defense cooperation that has become more frequent as North Korea becomes more aggressive.

In a statement last week, Kim Yo Jong, the sister of North Korean leader Kim Jong Un, vowed that her country will use the Pacific Ocean as a "firing range" if the U.S. and its allies continue their hostile actions.