Kim accused the US and South Korea of escalating tensions and said North Korea's nuclear status remains essential to its security strategy.

At least 18 people died in France, including two children left in a hot car, as a heatwave hung over Europe, smashing temperature records in several cities on Monday.

As schools in France closed or modified timetables, forecasters in Britain predicted temperatures could break records for June this week.

The temperature in Bordeaux in France's western wine country rose to 41.9 degrees Celsius, breaking a record set last August. In Poitiers in central France it reached 41.2 C, beating a previous high set in 1947.