Pyongyang is a "bad toothache" for Beijing, but instead of treating it with a root canal, the mainland uses painkillers instead, Hayden said at a Johns Hopkins University event, Yonhap News reported early on Wednesday.

Washington's deployment of the THAAD missile defense system in could push to take more action against , according to former CIA Director Michael Hayden.

To , increasing the toothache's pain is key, said the retired Air Force general.

"Frankly, we did that. President Obama did that with the deployment of THAAD," Yonhap quoted Hayden as saying.

The first elements of America's missile defense technology known as the Terminal High Altitude Area Defense system (THAAD) have already arrived in South Korea to counter .

"We planted this high-end air defense system in South Korea that has obvious implications for the Chinese because the radar fans go all the way through Manchuria," Hayden said, according to Yonhap.

"There are things like that, actions we could take that are logical and useful to defend against this particular kind of threat that we should not forgo merely because it would ."

Deploying THAAD to Japan was another means to increase pressure on China, Yonhap quoted Hayden as saying.