U.S. sends two aircraft carriers to South China Sea despite China's warning.

The USS Ronald Reagan and USS Nimitz are set to hold some of the U.S. Navy's largest exercises in recent years in the South China Sea from Saturday, reported The Wall Street Journal.

The move came after China rebuked U.S. accusation that China's military drill destabilizes the situation in the region on Friday. 

In response to U.S. Defense Department's "concerns" over China's military drills in the region, the Chinese Foreign Ministry asserted that holding military drills in the South China Sea is within the country's sovereignty and reasonable. 

"Some countries outside the region often travel thousands of miles to the South China Sea to engage in large-scale military activities, and show off their power, which is the fundamental reason that affects the stability in the South China Sea," said Zhao Lijian, a spokesperson of the ministry.

While the US has denied that its exercise is a countermeasure against China's military games in the sea, it has stated that it seeks to support a free and open Indo-Pacific region.

China meanwhile has been conducting Naval drills near the Paracel Islands claimed both by Vietnam and China. They will be conducted from 1 to 5 July. They have been criticized by both Vietnam and the Philippines.