Four U.S. F-22 stealth fighters are flying over South Korea amid growing tensions following North Korea's rocket launch.
The high-tech planes capable of sneaking past radar undetected were seen flying near a U.S. air base near Seoul on Wednesday.
Pyongyang will likely view the arrivals of the planes as a threat as they are a clear show of force against the country.
The United States often sends powerful and sophisticated warplanes to South Korea in times of tension with North Korea.
Last month, the United States sent a powerful nuclear-capable B-52 bomber to South Korea following North Korea's fourth nuclear test.