LONDON (Reuters) - Britain is looking at all ways it can put pressure on North Korea after Pyongyang conducted a nuclear test, Prime Minister Theresa May s spokeswoman said on Monday, adding that peaceful diplomatic solutions were preferable. North Korea conducted its sixth nuclear test on Sunday, prompting a warning of a  massive  military response from the United States if it or its allies were threatened.  As the prime minister made clear yesterday ... our focus is on working with partners to increase pressure on Korea and find a diplomatic resolution to the crisis,  May s spokeswoman told reporters.  She said we want to increase the pace of implementation of existing sanctions and look at other measures ... It s our view in the UK that ... peaceful, diplomatic means are best.  