A squadron of U.S. F-117 stealth fighters deployed to South Korea three months ago will remain in the country until November.

An official at the South Korean Defense Ministry said Friday that the radar-evading combat aircraft, also known as "Nighthawks", and their crew would continue to conduct training aimed at familiarizing themselves with the geographical features of the Korean Peninsula until November, at the latest.

The delay of the Nighthawks' re-deployment is seen as a strategic move by the United States to exert pressure on North Korea, which recently announced it had converted plutonium from 8,000 spent nuclear fuel rods into weapons.

A five-month deployment of a Nighthawk squadron to the country is an unusual move for Washington. The U.S. military dispatched the fighters to South Korea twice in 1993 and 1996, only to withdraw them after two to three months.