Q&A: Where the UK stands on North Korea’s nuclear tests

As tensions heighten after North Korea carried out its sixth and most powerful test of a nuclear device, here’s a look at what the UK’s involvement might be if the crisis escalates.

Additional restrictions on a range of imports and on North Korean workers overseas could be considered, the Prime Minister’s spokeswoman said last week. On her visit to Japan, Theresa May made clear she wanted to increase the pace of sanction implementation. Her spokeswoman said there were “further sanctions” which could be considered when asked whether they could include an oil blockade.

The UK’s nuclear weapons would never be engaged in a Korean conflict, according to Tom Plant, director of proliferation and nuclear policy at think tank the Royal United Services Institute (RUSI). He told the Press Association that Britain would more likely support any conflict through intelligence and logistics and in “whatever way was sensible”, but said: “I think all parties recognise that Britain’s role in any escalation or in the end stage of any conflict would be pretty limited.”

It would be highly unlikely for North Korea to take fire at Britain, Mr Plant said. He said there was “no circumstance that I can think of” where the country would threaten the UK with a nuclear weapon, except if British forces were marching north in support of the US military – and North Korea calculated that they may be able to deter the Americans by striking at allies. He said it was more likely that North Korea would use the weapons against US bases in the region: “If the North Koreans are using their weapons… they are going to be using them against the targets that count, and that’s not us.”

After Pyongyang detonated its largest-ever nuclear test explosion on Sunday, South Korea has fired missiles into the sea to simulate an attack on the North’s main nuclear test site. Donald Trump’s administration has warned that any threat to the US or its allies would trigger a “massive military response” against the secretive east Asian state. When asked by a reporter during a church visit if he would attack the North, Mr Trump is reported to have said: “We’ll see.” US defence secretary Jim Mattis has briefed Mr Trump about the military options available if the crisis escalates, adding that Washington was capable of launching an “effective and overwhelming” response. He said that while the US was “not looking to the total annihilation” of North Korea there were “many options to do so”.