SEOUL — North Korea has announced that it successfully launched its largest intercontinental ballistic missile (ICBM) in a test on Thursday.

The Hwasong-17 was first unveiled in 2020 at a parade where its colossal size surprised even seasoned analysts.

Thursday's launch marked the first time the country tested an ICBM since 2017.

ICBMs are long-range missiles, capable of reaching the US. N Korea is banned from testing them and has been heavily sanctioned for doing so before.

State media said leader Kim Jong-un directly guided Thursday's test and the weapon was key to deterring nuclear war.

Ankit Panda from the Carnegie Endowment for International Peace called the launch a "significant milestone" for North Korea's nuclear arsenal.

"This test was long telegraphed and continues North Korea's efforts to improve its nuclear deterrent," he told the BBC.

Thursday's missile launch was tracked by militaries in Japan and South Korea - Japanese officials said it flew to an altitude of 6,000 km (3,728 miles) and fell in Japanese waters after flying for more than an hour.

Its altitude surpasses that of a previous missile - the Hwasong-15 - which reached an altitude of 4,500km (2,800 miles) in a series of tests carried out by North Korea in 2017.

Experts estimated the Hwasong-15, if it had been fired on a standard trajectory, could have travelled more than 13,000km (8,080 miles), placing any part of the continental United States within reach.

The new missile would be able to travel higher and further than this.

The latest test comes after a flurry of missile tests in recent weeks, some of which the US and South Korea said were in fact parts of an ICBM system. Pyongyang claimed these were satellite launches at the time.

The ICBM test is being seen as a major escalation by the North and has been condemned by the UN, its neighbours and the US.

The United States called it a "brazen violation" of UN Security Council resolutions.

"The door has not closed on diplomacy, but Pyongyang must immediately cease its destabilising actions," White House spokeswoman Jen Psaki said.

UN Secretary General Antonio Guterres called the launch "a significant escalation of tensions in the region", while South Korean president Moon Jae-in said it was a "breach of the suspension of intercontinental ballistic missile launches promised by Chairman Kim Jong-un to the international community".

After the launch, state media quoted Kim as saying that the country was preparing for a long confrontation with US imperialism. — BBC