North Korea fired two cruise missiles off the west coast Sunday, the Joint Chiefs of Staff (JCS) said Wednesday, Pyongyang's first missile test in about a year seen as aimed at testing the administration of US President Joe Biden without being too provocative.

"We detected two projectiles presumed to be cruise missiles fired from the North's western port county of Onchon early Sunday," a JCS officer told reporters.

He refused to disclose other details, including their exact type, flight range and apogee, only saying that South Korean and US authorities have been analyzing details and closely monitoring related moves.

Leader Kim Jong-un does not appear to have observed the latest firings, according to sources.

Rep. Ha Tae-keung of the main opposition People Power Party (PPP) said in a Facebook post that the launches took place at around 6:36 a.m. on Sunday. He added that South Korea and the US were aware of the firings but decided not to make them public.

Unlike ballistic missiles, cruise missiles are not banned under UN Security Council resolutions on North Korea. Pyongyang has maintained a self-imposed moratorium on nuclear and long-range missile testing since late 2017.

The United States made no big deal out of the firings, with Biden saying "nothing much has changed" and senior administration officials saying the launches were not in violation of UN Security Council resolutions.

The launches mark the North's first known missile test since April 14, 2020, when it launched multiple short-range cruise missiles into the East Sea on the eve of the late national founder's birthday and South Korea's general elections.

At that time, the missiles, believed to be Kumsong-3 coastal defense missiles, also known as the KN-19 by the US, were fired from its eastern coastal town of Muncheon, and flew around 150 kilometers before splashing into waters off the East Sea.

"Sunday's firings might be seen as part of its ongoing wintertime military exercise. There is nothing more that we feel the need to explain about further," another officer said.

Pyongyang launched wintertime drills in December, which usually continue through the end of March, according to officials.

The latest test took place three days after South Korea and the US staged their springtime joint military exercise for nine days until Thursday.

Though Seoul and Washington said that the exercise is defensive in nature and was staged in a smaller scale amid the COVID-19 situation and for peace efforts with the North, Pyongyang lodged a strong protest and threatened to scrap an inter-Korean military agreement.

The move also came days after US Secretary of Defense Lloyd Austin and the Secretary of State Antony Blinken visited South Korea and agreed with their counterparts here -- Defense Minister Suh Wook and Foreign Minister Chung Eui-yong -- to work together closely to resolve the North's nuclear and missile issues as their top priority.

Amid little progress in negotiations with the US, North Korea has advanced its conventional weapons and showed off several new types of missiles, including a new inter-continental ballistic missile (ICBM) and submarine-launched ballistic missiles (SLBMs).

Rather than test-firing ballistic missiles, however, the North seems to have opted for taking low-intensity steps, in an apparent move to send warnings to South Korea and the US while remaining open to chances for dialogue, according to experts.

South Korea and the US also appear to be downplaying the North's recent missile activity.

The latest test was made public belatedly Wednesday after reports by foreign press outlets.

JCS officials said that they do not announce all missile activities of the North, particularly in cases where they do not involve ballistic missiles.

"The decision not to announce the recent firings was made jointly with the US side. We are closely monitoring the North Korean military activities, while maintaining a firm joint readiness posture," a JCS officer said.

North Korea has also remained mum on the latest test.

Ballistic missiles have a much longer range than cruise missiles of the same size and move quickly along their flight path. Ballistic missiles are also deemed more threatening, as they are designed to deliver nuclear weapons.

But low-altitude sea-skimming cruise missiles are hard to detect and boast a high accuracy rate as they employ so-called waypoint maneuvering, which allows the weapon to reorient itself during flight and hit a target, according to experts.

"During recent military parades, the North also unveiled new cruise missiles. This test could aim at testing them," a source said.

Pyongyang has ignored the Biden government's offer to resume talks.

On Thursday, Choe Son-hui, the North's first vice foreign minister, issued a statement and said any contact and dialogue with the US can be possible only when Washington rolls back its "hostile policy" toward it.

"In order for a dialogue to be made, an atmosphere for both parties to exchange words on an equal basis must be created," the statement read.

The US is scheduled to hold a security meeting with South Korea and Japan to discuss how to deal with issues of North Korea. (Yonhap)