Boris Johnson has condemned the "reckless" North Korean nuclear test and warned that being able to fit a warhead to a missile would present a "new order of threat" from Kim Jong Un's regime.
The Foreign Secretary said the UK's view was that "peaceful diplomatic means" are the best way to resolve the crisis in the Korean peninsula.
In an attempt to play down the threat of conflict he said that "none of the military options are good" - but added that "it is of course right to say that all options are on the table".
The detonation of the nuclear device was North Korea's sixth and most powerful test to date.
Pyongyang called the test a "perfect success" but it has led to condemnation from around the world.
US President Donald Trump branded North Korea "a rogue nation" whose "words and actions continue to be very hostile and dangerous" to the United States.
Mr Trump tweeted that North Korea "has become a great threat and embarrassment to China, which is trying to help but with little success".
Mr Johnson called for "common sense" to prevail in the crisis and urged Beijing to put further pressure on Kim's regime.
He said: "There is no question that this is another provocation, it is reckless, what they are doing is 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.
"We have to consider how to respond and it's our view in the UK, overwhelmingly, that peaceful diplomatic means are the best."
Mr Johnson said: "Over the 30 year history of North Korea's attempt to acquire nuclear weapons there have been tough moments and moments when they have backed down again.
"We are working to see if we can get some common sense here."
Asked how close the crisis was to conflict, Mr Johnson said: "It's certainly our view that none of the military options are good. It is of course right to say that all options are on the table, but we really don't see an easy military solution."
The distance between North Korea and South Korea's capital Seoul is small and "they could basically vapourise" large parts of the population even with conventional weapons, he warned.
"So that's not really very easy to threaten and to deliver," he said.
"Much more productive we think is to continue with the international diplomatic effort."