Pentagon slams North Korea's missile test

The Pentagon has slammed the North Korean missile tests.

The Pentagon has strongly condemned North Korea's latest missile test. (AAP)

The Pentagon has strongly condemned North Korea's latest missile test, adding that the United States' commitment to protect the homeland and allies such as Japan and South Korea was "ironclad".

Pentagon spokesman Captain Jeff Davis on Monday told reporters that North Korea's "unlawful weapons programs" were a clear and grave threat to national security.

"We are capable of defending against a North Korean ballistic missile attack and will take all necessary measures to deter and defeat threats to our and our allies' territories and citizens," Davis added.

North Korea said it had successfully test-fired a new type of medium- to long-range ballistic missile the previous day, claiming advances in a weapons program it is pursuing in violation of UN resolutions.

The missile was propelled by a solid-fuel engine and was an upgraded, extended-range version of its submarine-launched ballistic missile that was tested successfully last August, according to North Korea's government-run KCNA news agency.

Davis said it appeared that the missile was an intermediate-range ballistic missile, the land-based variant of what North Korea has launched from submarines in the past.