LONDON, Sept 3 (Reuters) - North Korea's latest nuclear test could represent a new order of threat, Britain's foreign minister Boris Johnson said on Sunday.

"There's no question that this is another provocation, it's reckless," he told Sky news. "They seem to be moving closer towards a hydrogen bomb which, if fitted to a successful missile, would unquestionably present a new order of threat."

Pyongyang conducted its sixth and most powerful nuclear test earlier on Sunday.

He said Britain's preference was for a diplomatic solution and that none of the military options relating to North Korea were palatable. (Reporting by William James; editing by John Stonestreet)