North Korea says carried out new test of solid-fuel ICBM

North Korea said Thursday it had successfully tested its new intercontinental ballistic missile, state media reported, as Pyongyang vented its fury after threatening to down US spy planes it said had violated its airspace.

The report from state-run KCNA news agency said the Hwasong-18 -- a new type of purportedly solid-fuel ballistic missile that has reportedly only been fired by the North once before, in April -- flew 1,001 kilometres at a maximum altitude of 6,648 km before splashing into the East Sea, also known as the Sea of Japan.

The flight time of around 70 minutes is also similar to some of North Korea's previous ICBM launches, experts said.

The launch, which KCNA said was guided by North Korean leader Kim Jong Un, was a "grand explosion" that shook "the whole planet", according to the report.

Kim also vowed that "a series of stronger military offensive" would be launched until the United States and South Korea change their policies towards the North, KCNA said.

The confirmation of the launch -- which the South Korean military had reported on Wednesday -- came as relations between the two Koreas are at one of their lowest points ever, with diplomacy stalled and Kim calling for increased weapons development, including tactical nukes.

In response, Seoul and Washington have ramped up security cooperation, vowing that Pyongyang would face a nuclear response and the "end" of its current government were it to ever use its nuclear weapons against the allies.

The launch "is a grave provocation that damages the peace and security of the Korean peninsula" and violates United Nations sanctions on Pyongyang, South Korea's military said, calling on North Korea to stop such actions.

The United Nations, United States and its allies, including France, also strongly condemned it.

"This launch is a brazen violation of multiple UN Security Council resolutions and needlessly raises tensions and risks destabilising the security situation in the region," US National Security Council spokesperson Adam Hodge said in a statement.

Pyongyang in February also launched a Hwasong-15, which flew a similar 989 kilometers.

Wednesday's launch came after North Korea on Monday accused a US spy plane of violating its airspace and condemned Washington's plans to deploy a nuclear missile submarine near the Korean peninsula.

A spokesperson for the North Korean Ministry of National Defence said the United States had "intensified espionage activities beyond the wartime level", citing "provocative" spy plane flights over eight straight days this month.

"There is no guarantee that such shocking accident as downing of the US Air Force strategic reconnaissance plane will not happen in the East Sea of Korea," the spokesperson added.

Kim's powerful sister Kim Yo Jong said that a US spy aircraft had violated the country's eastern airspace twice on Monday, according to a separate statement.

Kim Yo Jong said North Korea would not respond directly to US reconnaissance activities outside of the country's exclusive economic zone, but warned it would take "decisive action" if its maritime military demarcation line was crossed.

The United States said in April that one of its nuclear-armed ballistic submarines would visit a South Korean port for the first time in decades, without specifying an exact date.

South Korean President Yoon Suk Yeol has ramped up defence cooperation with Washington in response, staging joint military exercises with advanced stealth jets and long-range heavy bombers.

Yoon is set to attend a NATO summit in Lithuania this week, seeking stronger cooperation over North Korea's growing threats.