A North Korean missile appears to have exploded just after it was launched, the US and South Korean militaries have announced, after they detected the latest in a series of weapons tests by the nuclear-armed state.

Key points: Missile was launched from Wonsan on North Korea's east coast, where several tests were made last year

Missile was launched from Wonsan on North Korea's east coast, where several tests were made last year North Korea is believed to be developing nuclear-armed missiles able to reach US mainland

North Korea is believed to be developing nuclear-armed missiles able to reach US mainland North Korea has dismissed threat of more sanctions, says will pursue "acceleration" of missile programmes

The launch attempt was made on Wednesday near the city of Wonsan, on North Korea's east coast, the same place it launched several intermediate-range missiles last year, all but one of which failed.

"US Pacific Command detected what we assess was a failed North Korean missile launch attempt ... in the vicinity of Kalma," US Pacific Command spokesman Commander Dave Benham said in a statement, referring to an air field in Wonsan.

"A missile appears to have exploded within seconds of launch," Mr Benham said, adding that a more detailed assessment was underway.

A South Korean military official also said the missile appeared to have exploded just after it was launched.

It was not clear what type of missile it was.

The South Korean defence ministry said it was conducting analysis to determine further details.

The increasing frequency of missile tests has fuelled a growing sense of urgency over how to respond to North Korea, which conducted its fifth nuclear bomb test in September.

It launched four ballistic missiles from near its west coast on March 6 and this week conducted a rocket engine test that its leader, Kim Jong-un, said marked "a new birth" of its rocket industry.

The latest launch came as the US envoy for North Korea policy, Joseph Yun, met his South Korean counterpart in Seoul to discuss a response to the North's weapons programmes.

US Secretary of State Rex Tillerson (L) says the time for a policy of strategic patience with North Korea has ended. ( AP: Jung Yeon-Je - file )

US: military options are on the table

Last week, US Secretary of State Rex Tillerson visited Japan, South Korea and China and said that a policy of strategic patience with North Korea had ended, and all options, including a military one, were on the table if North Korea threatened South Korean or US forces.

US officials stressed however that tougher sanctions will be the likely response for the time being, and a senior US official said on Monday the Trump administration was considering these as part of a broad review of North Korea policy.

North Korea is believed to be working to develop nuclear-tipped missiles that can reach the US mainland, but experts believe it is still several years away from that capability.

On Tuesday, a North Korean diplomat dismissed the threat of more sanctions and said his government would pursue an "acceleration" of its nuclear and missile programs, including a "pre-emptive first strike capability" and an inter-continental ballistic missile.

'Treasured sword of justice'

The North's official Korean Central News Agency reported on Monday that an unnamed North Korean Foreign Ministry spokesman had slammed Mr Trump for adopting the same policies as former President Barack Obama.

"Tillerson admitted the failure of the US efforts to denuclearise the DPRK for 20 years and end Obama's policy of 'strategic patience' during his recent tour," the official was quoted as saying.

"Now Tillerson is repeating what Obama touted ... until he left the White House.

"The nuclear force of the DPRK is the treasured sword of justice and the most reliable war deterrence to defend the socialist motherland and the life of its people.

"If the businessmen-turned-US authorities thought that they would frighten the DPRK, they would soon know that their method would not work."

ABC/wires