The US is thought to be deploying a Virginia-class attack submarine to South Korea against North Korea within days of Pyongyang's rocket launch. The sophisticated vessel is likely intended as a show of deterrence to the North.

"The US Navy's nuclear-powered submarine USS North Carolina is coming to South Korea as far as I know," an unnamed military official told South Korea's Yonhap news agency. A formal statement regarding the potential deployment is awaited.

The submarine, which can travel up to 46kms an hour, can be equipped with Tomahawk all-weather cruise missiles and state-of-the-art torpedoes. It is also expected to be joined by USS John C Stennis, a Nimitz-class supercarrier, which is expected to take part in joint military exercises. However, it is not known whether the submarine was originally a part of the naval military drills.

The US and its allies in the region – Japan and South Korea – usually step up their military activities whenever North Korea resorts to a major provocation such as the recent satellite launch. Shortly after Pyongyang's fourth nuclear test – which was conducted on 6 January violating UN regulations – US forces flew powerful B-52 bombers over the region.

"The US military will send a warning message and reassert its commitment to the defence of South Korea through the deployment of the key strategic assets to the Korean Peninsula," the military official added. Washington's actions are bound to further infuriate the North, which considers the US's activities, including the military manoeuvres, as preparation for a full-fledged war.