North Korea early Friday launched a short-range ballistic missile toward its eastern waters and flew warplanes near the border with South Korea, further raising animosities triggered by the North’s recent barrage of weapons tests.

The North Korean moves suggest it would keep up a provocative run of weapons tests designed to bolster its nuclear capability for now. Some experts say North Korea would eventually want the United States and others to accept it as a nuclear state, lifting economic sanctions and making other concessions.

South Korea’s Joint Chiefs of Staff said in a statement the missile lifted off from the North’s capital region at 1:49 a.m. Friday (1649 GMT Thursday; 12:49 p.m. EDT Thursday). It said South Korea boosted its surveillance posture and maintains military readiness in close coordination with the United States.

Japanese Defense Minister Yasukazu Hamada said the missile flew on an “irregular” trajectory — a possible reference to describe the North’s highly maneuverable KN-23 weapon modeled on Russia’s Iskander missile.

“Whatever the intentions are, North Korea’s repeated ballistic missile launches are absolutely impermissible and we cannot overlook its substantial advancement of missile technology,” Hamada said. “North Korea’s series of actions pose threats to Japan, as well as the region and the international community, and are absolutely intolerable.”

He said the missile traveled as far as 650 kilometers (403 miles) at the maximum altitude of 50 kilometers (30 miles) before landing in waters between the Korean Peninsula and Japan.

The U.S. Indo-Pacific Command said in a statement the North Korean launch didn’t pose an immediate threat to U.S. personnel or territory, or to its allies, adding that the U.S. commitments to the defense of South Korea and Japan remain “ironclad.”

It was the latest in a series of missile launches by North Korea in recent weeks.

North Korea said Monday that its missile tests in the past two weeks simulated nuclear attacks on key South Korean and U.S. targets. It said the tests included a new intermediate-range missile that flew over Japan and demonstrated a potential range to reach the U.S. Pacific territory of Guam, and a ballistic missile fired from an inland reservoir, a first for the country.

North Korea said the weapons tests were meant to issue a warning to Seoul and Washington for staging “dangerous” joint naval exercises involving a U.S. aircraft carrier.

Friday’s launch was the North’s second since its announcement on the simulation of nuclear strikes. Some observers had predicted North Korea would likely temporarily pause its testing activities in consideration of its major ally China, which is set to begin a major political conference Sunday to give President Xi Jinping a third five-year term as party leader.

North Korea said leader Kim Jong Un supervised the test-launches Wednesday of long-range cruise missiles that he said successfully demonstrated his military’s expanding nuclear strike capabilities.

After the tests, Kim praised the readiness of his nuclear forces, which he said were fully prepared for “actual war to bring enemies under their control at a blow” with various weapons systems that are “mobile, precise and powerful.” He also vowed to expand the operational realm of his nuclear armed forces, according to KCNA.

The urgency of North Korea’s nuclear program has grown since it passed a new law last month authorizing the preemptive use of nuclear weapons over a broad range of situations.

Most of the recent North Korean tests were mostly of short-range nuclear-capable missiles targeting South Korea. Some experts say North Korea’s possible upcoming nuclear test, the first of in five years, would be related to efforts to manufacture battlefield tactical warheads to be placed on such short-range missiles.

These developments sparked security jitters in South Korea, with some politicians and scholars renewing their calls for the U.S. to redeploy its tactical nuclear weapons in South Korea as deterrence against intensifying North Korean nuclear threats.

South Korea’s Joint Chiefs of Staff said in a separate statement that North Korea had flown warplanes, presumably 10 aircraft, near the rivals’ border late Thursday and early Friday, prompting South Korea to scramble fighter jets.

The North Korean planes flew as close as 12 kilometers (7 miles) north of the inter-Korean border. South Korea responded by scrambling F-35 jets and other warplanes, according to the Joint Chiefs of Staff.

There were no reports of clashes. A similar incident took place last week, but it was still uncommon for North Korea to fly its warplanes near the border. Also, in the previous flight last week, North Korean warplanes flew much farther away from the border.

North Korea’s military early Friday accused South Korea of carrying out artillery fire for about 10 hours near the border. It didn’t say whether the artillery fire was an exercise or firing at North Korea. The North Korean military said it took unspecified “strong military countermeasures” in response.

“The (North) Korean People’s Army sends a stern warning to the South Korean military inciting military tension in the front-line area with reckless action,” an unidentified spokesman for the General Staff of the Korean People’s Army said in a statement carried by KCNA.

The public affairs office at the South Korean Defense Ministry said it had no immediate comment.

(AP)