North Korea fired two ballistic missiles early Thursday from near Pyongyang toward the Sea of Japan, the sixth round of launches since late September, after a U.S. aircraft carrier was redeployed to the waters, the Japanese government and the South Korean military said.

The launches came just two days after Pyongyang fired a ballistic missile over the Japanese archipelago for the first time in five years, and a day after the nuclear-powered aircraft carrier Ronald Reagan was redeployed to the Sea of Japan for a joint drill.

A television screen at Seoul Station shows news of North Korea's launch of ballistic missiles on Oct. 6, 2022. (Kyodo)

The United States, South Korea and Japan conducted the drill in waters off the Korean Peninsula on Thursday in response to the North's missile provocation, the South's Joint Chiefs of Staff said.

The North Korean projectiles fell outside Japan's exclusive economic zone and flew between 350 and 800 kilometers at a maximum altitude of 50 to 100 km, Defense Minister Yasukazu Hamada told reporters, adding there were no reports of damage to Japanese aircraft and ships.

The JCS said two short-range ballistic missiles were launched near the Samsok area in Pyongyang between 6:01 a.m. and 6:23 a.m. The first one travelled about 350 km while reaching an altitude of about 80 km at a speed of about Mach 5 and the second one flew about 800 km at the maximum altitude of about 60 km at a speed of around Mach 6, it added.

Speaking to reporters, Japanese Prime Minister Fumio Kishida slammed North Korea's repeated firings of missiles over a short span of time as "absolutely unacceptable." Tokyo lodged a protest with North Korea through its embassy in Beijing, Hamada said.

South Korean President Yoon Suk Yeol vowed to protect his people through his nation's strong alliance with the United States and security cooperation between Seoul, Washington and Tokyo.

The U.S. State Department also condemned the missile tests, saying North Korea's launches were in violation of U.N. Security Council resolutions and posed "a threat" to neighbors and the international community.

While reiterating its call for Pyongyang to engage in dialogue, a department spokesperson said in a statement that U.S. commitments to the defense of Japan and South Korea remained "ironclad."

Japanese Prime Minister Fumio Kishida speaks to reporters at his office in Tokyo on Oct. 6, 2022. (Kyodo)

North Korea's Foreign Ministry issued a statement early Thursday saying it "strongly condemns" the United States and other countries for referring Tuesday's ballistic missile launch to the U.N. Security Council, state-run media reported.

The ministry said Tuesday's launch was part of "just counteraction measures" in response to the U.S.-South Korea drills that were "escalating the military tensions" on the Korean Peninsula, according to the official Korean Central News Agency.

As for the redeployment of the U.S. aircraft carrier, North Korea was "watching the U.S. posing serious threat to the stability of the situation" on the Korean Peninsula and its vicinity, the report said.

The JCS said South Korea's Sejong the Great guided missile destroyer, Japan's guided missile destroyer Chokai and the U.S. aircraft carrier were deployed for the joint drill held in South Korea's eastern waters on Thursday.

The JCS said it expects the drill to reaffirm operational capabilities against North Korea's ballistic missile provocations.

The Ronald Reagan participated in joint drills with South Korea's navy from Sept. 26 to 29, before joining the first anti-submarine exercise in five years in the Sea of Japan held by the United States, South Korea and Japan, on Sept. 30.

The carrier's home port is Yokosuka, near Tokyo.

Thursday's launches by North Korea marked the sixth round of firings since Sept. 25. The missile on Tuesday covered the longest distance ever for a launch by Pyongyang.

Since the start of the year, North Korea has conducted more than 20 rounds of ballistic missile tests in violation of Security Council resolutions. Concerns have been growing that Pyongyang will conduct its seventh nuclear test and first since September 2017 in the near future.

In response to the latest move, Takehiro Funakoshi, head of the Foreign Ministry's Asian and Oceanian Affairs Bureau, reaffirmed close cooperation in phone calls with his U.S. and South Korean counterparts Sung Kim and Kim Gunn over boosting deterrence and handling the matter at the U.N. Security Council.

On Wednesday, the Security Council failed to take unified action on the North Korean missile launch over Japan, with China and Russia criticizing the recent joint military drill conducted by the United States, South Korea and Japan.

In New York, Japanese Ambassador to the United Nations Kimihiro Ishikane said Thursday's missile launches showed Pyongyang was "taking advantage of inaction of the U.N. Security Council."

In May, China and Russia vetoed a Security Council resolution drafted by the United States seeking to impose tougher sanctions on North Korea following its ballistic missile tests this year.

It was the first rejection of a Security Council resolution aimed at preventing North Korea from developing nuclear weapons and missiles since 2006, when the first sanctions were adopted.

U.S. aircraft carrier Ronald Reagan (C) and other navy vessels of the United States, Japan and South Korea conduct joint drills in the Sea of Japan on Sept. 30, 2022. (Photo courtesy of Japanese Maritime Self-Defense Force)(Kyodo)