A US analyst says that North Korea may have relocated a long-range missile from its launch site for repairs after it test-fired a similar missile last month.

A security expert from the US Brookings Institution, Michael O'Hanlon, spoke on Friday in an interview with Radio Free Asia.

He claimed that the North was not happy about the performance of their Daepodong-2 after its launch last month. He added that the North Koreans might be trying to fix the missile now.

O'Hanlon also said that it suggests that there may have been a very basic problem with the structure or design of the rocket, or that some of the rocket's fundamental mechanics and machinery could have been flawed.

Pyongyang launched seven ballistic missiles in early July including a Daepodong-2, which is believed to be capable of reaching as far as the western United States.