Tensions rise as North Korea reacts to US aircraft carrier's arrival in South Korea

North Korea has condemned the arrival of a US aircraft carrier battle group in South Korea, calling it a provocation and threatening to use nuclear weapons in self-defense. Despite its advancing nuclear arsenal, experts believe North Korea is unlikely to use its nukes first, but will continue to upgrade its weapons. The USS Ronald Reagan arrived in Busan as part of an agreement to increase the temporary deployments of US military assets in response to North Korea's growing nuclear program. North Korea argues that it developed nuclear weapons to counter perceived threats from the US and South Korea.