The nuclear-powered USS Alexandria is a 360-foot fast-attack submarine equipped with Tomahawk missiles and MK48 torpedoes.

A nuclear-powered US submarine has made a port call in South Korea, and defense officials in Pyongyang are bristling. A spokesperson says the move further escalates military tensions in the region.

North Korea has accused the US of engaging in a "hostile military act" and posing a "grave security threat" to the country by sending a nuclear submarine to a South Korean port. At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.