US has moved three B-2 bombers around the Korean Peninsula along with several hundred military personnel ahead of the Winter Olympics to be held in South Korea next month, reports said.
The military build-up comes even as both Koreas engage in talks over the Pyeongchang Winter Olympics.
The Trump administration had earlier postponed military drills with South Korea but had continued its military presence even as it welcomed talks between the two countries.
In a statement, the US government said the deployment is intended to provide leaders with "deterrent options to maintain regional stability."
The US government has sent the USS Carl Vinson aircraft carrier to the western Pacific. The Navy called it a "regular scheduled deployment".
Meanwhile, the USS Wasp reached southern Japan. USS Ronald Reagan aircraft carrier is also in the region off Japan. The 40,00-ton, 844-foot-long Wasp is an aircraft carrier built in the 80s. It hosts Marine Corps F-35B stealth fighter jets.
In addition, several thousand marines are also deployed in the area.
The North Korean government in a statement said: "Such moves are an unpardonable military provocation chilling the atmosphere for improved inter-Korean relations."