North Korea has fired a suspected intercontinental ballistic missile (ICBM), Japanese and South Korean officials report.

The long-range missile flew for more than an hour before landing short of Japanese waters on Wednesday morning.

Pyongyang's launch comes after it threatened retaliation against what it said were recent US spy plane incursions over its territory.

Earlier this week it threatened to shoot down such planes.

Washington has dismissed the accusations, saying its military patrols are in line with international law.

Security concerns have ramped up on the peninsula this year after North Korea tested new weapons. The country also conducted a record number of missile launches in 2022 including ones capable of reaching US territory.

In response, the US and South Korea have increased their joint military drills around the peninsula.

Pyongyang so far has continued with its missile launches - testing a new ICBM in April which it described as its "most powerful" missile to date. It also tried to launch a spy satellite in May which failed.

North Korea's missile on Wednesday flew eastwards from Pyongyang for more than an hour before landing in the sea west of Japan around 11:15 local time (02:15 GMT), the Japanese Coast Guard reported. The high-angled flight covered a 1,000km (621 miles) distance said South Korea's military.

South Korean and US officials met immediately after Wednesday's launch, issuing a statement reiterating their "strengthened" joint defence.

"We strongly condemn North Korea's launch of a long-range ballistic missile as a grave provocative act that harms the peace and stability of the Korean peninsula and the international community and is a clear violation of UN Security Council resolutions," the South Korean Joint Chiefs of Staff said.

South Korean President Yoon Suk-yeol also convened an emergency meeting of his national security council from Lithuania. where he is attending the Nato summit.

North Korea's last launch was in mid-June when it fired two short-range ballistic miles in response to US and South Korean drills. It last test-fired an ICBM in February.

ICBMs are particularly worrying because of their long range, including mainland United States.

When Pyongyang tested one in November 2022, it fired it at a high-angle, short-range trajectory. But this could have reached the US mainland if it were fired at a lower trajectory, the Japanese government said at the time.

Wednesday's launch comes days after heated rhetoric from Pyongyang warning the US to stop its air patrols and proposal for a nuclear submarine to visit Korean waters.

On Monday, North Korean leader Kim Jong Un's powerful sister, Kim Yo-jong, accused a US surveillance plane of violating North Korea's air space. She said if such flights continued, there would be "shocking" consequences.

Such rhetoric falls into Pyongyang's pattern of "inflating external threats to rally domestic support and justify weapons tests", said Prof Leif-Eric Easley, a North Korea expert at Ewha University in Seoul.

He added Pyongyang often timed launches to "disrupt what it perceives as diplomatic coordination against it", referring to the Nato summit where South Korea and Japan leaders were due to meet on the sidelines.

Despite UN sanctions, Kim Jong-Un has repeatedly vowed to increase his country's production of nuclear warheads and development of more powerful weapons.

Analysts are expecting the latest North Korean hardware to be on display in late July when the country celebrates the anniversary of the Korean War armistice, known in the country as Victory Day.