SINPO, North Korea - South Korean and Japanese officials say North Korea test fired at least one ballistic missile from its port city of Sinpo, Hamgyong province into the Sea of Japan, Tuesday morning, CNN reports.

South Korea's Joint Chiefs of Staff (JCS) also confirmed that it appeared to be a submarine-launched ballistic missile (SLBM).

The South Korean Defense Ministry supported the above information from the JCS, also saying the test launch was likely fired from a submarine, though this has yet to be confirmed.  

There is some dispute over how many missiles were launched early Tuesday. While Japan's Deputy Secretary General Yoshihiko Isozaki said two ballistic missiles were fired, South Korea's military reported that only one was launched.

In any case, officials in both countries appear to be dismayed by the launch. 

Isozaki touched on this, stating, "North Korea's latest actions threaten the peace and security of Japan and the region. Furthermore, the continued ballistic missile launches pose a serious challenge not just for Japan but for the entire international community."

Japan's Deputy Secretary General added that the test launch violated UN Security Council resolutions. The UN generally considers ballistic missiles to be more threatening than cruise missiles as they can carry more powerful payloads, have a longer range, and are able to fly faster.

Japanese Prime Minister Fumio Kishida also expressed disapproval of the launch. He took to social media to post that the country would "respond resolutely" to North Korea's action in a tweet on Tuesday.

South Korea's National Security Council (NSC), likewise, voiced its "deep regret" over the incident, according to a text sent to reporters by the Presidential Office Blue House. The text indicated that the missile launch occurred while South Korea, the United States, China, Japan and Russia were in the midst of discussions aimed at establishing peace in the Korean Peninsula.

After the launch, NSC standing committee members reportedly urged North Korea to increase its communication with other countries in order to promote stability in the region.

According to the BBC News, North Korea has initiated a series of missile tests in recent weeks, including the testing of weapons that it referred to as hypersonic and long-range weapons.