Nikki Haley, US ambassador to the UN, said her country did not want conflict but its patience was "not unlimited". Its leader, Kim Jong-un, was "begging for war", she added.
North Korea's biggest ally, China, has called for dialogue, so the crisis can be "resolved peacefully".
All-out war would be catastrophic in terms of lives lost. It might potentially involve the use of nuclear weapons - the first time since the closing stages of the Second World War - which could set a terrifying new precedent in international affairs.
At its close, after terrible destruction, North Korea would no longer exist. That is a given, hence the hope that the Pyongyang regime is rational and understands the risks involved. Its behaviour, though, amounts to very, very high-stakes brinksmanship.
It's reached wind speeds of 220km/h (140mph), which are likely to strengthen in the next 48 hours, bringing torrential rain, storm surges and a threat to life. Hurricane Irma is expected to hit the Leeward Islands by the end of Tuesday (local time), although it's too early to predict its path after that, according to US weather forecasters. Florida and Puerto Rico have declared states of emergency in preparation for the possibility it will reach them.
Things have reportedly not gone very smoothly - or quickly - between UK and European Union negotiators during the early stages of trying to reach a Brexit deal. Later, Brexit Secretary David Davis will give the House of Commons his view on the talks, which Prime Minister Theresa May says she wants to "intensify". This comes ahead of a debate on Thursday on the government's EU withdrawal bill, which would transfer existing EU law into UK law. Labour wants to make six amendments to it - the government doesn't.
At the moment, the main problem is money, which is hardly a surprise. The UK wants the bill for its financial obligations on exit to be as low as possible. All the other countries in the EU want it to be as high as possible, because when the UK leaves there will be a hole in the EU budget and they will have to cover the shortfall.
The news that the Duke and Duchess of Cambridge are expecting a third child makes headlines, with the Daily Express focusing on the duchess's severe morning sickness, something she also suffered during her previous pregnancies. "Heir we go again," puns the Metro. The Guardian leads on US diplomat Nikki Haley's remark that North Korea's Kim Jong-un is "begging for war". And the i says Theresa May is looking to end the cap on public sector pay rises.
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12:30 A French judge rules on the case the Duke and Duchess of Cambridge brought against Closer magazine for publishing topless photos of the duchess while the royal couple were on holiday in 2012.
1997 Mother Teresa, the Nobel Peace Prize winner who devoted her life to helping the sick and the poor, dies at the age of 87.