SEOUL, South Korea—North Korea boasted Friday that the new intercontinental ballistic missile it just test-launched is “the world’s strongest,” a claim seen as pure propaganda after experts assessed it as being too big to be useful in a war situation. The ICBM launched Thursday flew higher and for a longer…

North Korea is boasting that its new intercontinental ballistic missile is “the world’s strongest,” a claim seen as pure propaganda after experts assessed it as being too big to be useful in a war situation.