North Korea launched more projectiles believed to be ballistic missiles in the early hours of Monday, which reportedly landed off Japan's coast.

Seoul's military said that North Korea fired "two short-range ballistic missiles from the Sukchon area," in a statement carried by the South Korean state news agency.

North Korea later announced it fired "two shots from multiple rocket launch system Monday," South Korea's leading Yonhap news agency reported.

Japan's Defense Ministry said both missiles landed in the East Sea, also known as the Sea of Japan between the Korean peninsula and Japan.

Yonhap News agency quoted North Korean politician Kim Yo-Jong, the sister of North Korea's leader in the early hours Monday, "It's up to the US how often North Korea will use [the] Pacific as its 'shooting range.'"

What was the reaction to the launch?

Japan's Defense Ministry strongly condemned North Korea's latest missile launch.

"North Korea's series of actions, including its repeated ballistic missile launches, threaten the peace and security of Japan, the region, and the international community," the ministry said. "Japan lodged a strong protest and forcefully condemned North Korea."

The US Indo Pacific Command stressed its "ironclad" commitments to the defense of South Korea and Japan after the missile launches, adding close consultations were being held with allies and partners.

"While we have assessed that this event does not pose an immediate threat to US personnel or territory, or to our allies, the missile launches highlight the destabilizing impact" of North Korea's unlawful weapons of mass destruction and ballistic missile programs, the US military said.

What prompted the latest missile launch?

Monday's missile launch came only two days after North Korea fired an intercontinental ballistic missile that landed off Japan's west coast. It described the strike as a "sudden launching drill."

The test came after Pyongyang warned of an "unprecedentedly persistent, strong" response to planned joint military drills by the United States and South Korea.

On Sunday, the US and South Korea held a joint air exercise in response to the intercontinental ballistic missile launch.

The latest missile launch is North Korea's third major weapons test this year.

Pyongyang's ballistic missile and nuclear weapons programs are banned under United Nations Security Council resolutions.

But the North's leaders say the weapons development is necessary to counter "hostile policies" by Washington and its allies.