The United States defence secretary Jim Mattis wants to "absolutely exhaust every possible avenue" to find a non-military solution to the crisis over North Korea's nuclear tests, Sir Michael Fallon has said.
The British Defence Secretary said global powers would leave "no stone unturned" in the coming days to find a diplomatic resolution to tensions which have intensified since the rogue state's sixth nuclear test, in which it claimed it had detonated a massive hydrogen bomb.
Sir Michael spoke as Russian president Vladimir Putin called for talks with Kim Jong-Un's North Korean regime, stressing that sanctions were not a solution.
US president Donald Trump's threat to unleash "fire and fury" on North Korea and accusation that South Korea was guilty of "appeasement" for wanting to reach out to its neighbours have been viewed as unhelpful in some quarters.
Asked if Mr Trump was planning for conflict, Sir Michael told BBC Radio 4's Today programme: "The United States is perfectly entitled to make all the preparations it needs to protect its people, its bases, its own homeland, and they are clearly doing that at the moment to make sure the president has all the options that he needs.
"But equally, Secretary Mattis and I and others across the administration are very clear that we have to absolutely exhaust every possible diplomatic avenue to get this situation under control now.
"That means working intensively in New York (at the UN) over the next few days to get a new resolution, it means looking at the existing sanctions and making sure they are properly enforced, it means looking at the European Union level at what sanctions can be applied there, and above all it means putting more pressure on China to deal with its neighbour."
Prime Minister Theresa May and Mr Trump discussed the crisis on the telephone on Tuesday and urged China to use its influence to ensure North Korea ends its "illegal acts". The pair also agreed to put extra economic pressure on Mr Kim's regime, although Moscow views sanctions as "useless and ineffective".
South Korea has meanwhile conducted live-fire exercises and displays of military capability amid the tensions.