Pyongyang, Mar 25 (IANS): North Korea on Friday confirmed that it successfully test-fired a new intercontinental ballistic missile (ICBM), marking an end to its self-imposed moratorium on long-range missile testing that had been in place since 2017.

According to Pyongyang's official Korean Central News Agency (KCNA), the Hwasong-17 was fired on Thursday "on the direct order of leader Kim Jong-un".

Making an on-site inspection of the test, Kim stressed his country would be "fully ready for long-standing confrontation with the US imperialists", Yonhap News Agency quoted the KCNA report as saying.

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, and fell in Japanese waters after flying for more than an hour, the BBC reported.

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 a ICBM since 2017.

ICBMs are long-range missiles, capable of reaching the US.

North Korea is banned from testing them and has been heavily sanctioned for doing so before.

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.

The missile's altitude surpasses that of a previous one -- the Hwasong-15 -- which reached an altitude of 4,500 km 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 13,000 km, placing any part of the continental US within reach.

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

It is believed to be the largest mobile ICBM designed to carry multiple warheads.

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 US 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.