The deployment of ballistic missile defense systems around North Korea by the United States and its allies could be an effective way to change China's strategic thinking about Pyongyang, a U.S. congressional report said.

The Congressional Research Service made the point in a recent report, "North Korea: U.S. Relations, Nuclear Diplomacy, and Internal Situation," saying Beijing would find it not in its national interest if provocative actions by the North lead to increased military deployments in the region.

When North Korea fired a long-range rocket in April 2012, a key focus of Chinese media coverage of the case was Patriot missile deployments that were made by the U.S. and its allies in response to the North's launch, the report noted.

A subtext of those reports was that the North's actions are feeding military developments that are not in China's interests, it said.

"As part of the efforts by the United States and its allies to change China's strategic thinking about North Korea, the BMD (ballistic missile defense) deployments may have an impact," the report said. "Many observers, particularly in the United States and Japan, argue that continued North Korean ballistic missile development increases the need to bolster regional BMD capabilities and cooperation."

As a key provider of economic assistance and diplomatic support for North Korea, China is considered by many the only country with any meaningful influence over Pyongyang, but Beijing has been unwilling to use that leverage.

Analysts say China, which considers North Korea as something of a buffer zone, fears that pushing Pyongyang too hard could lead to its collapse, instability on its border and ultimately the emergence of a pro-U.S. nation next door.

China has a track record of providing diplomatic support for the North and softening sanctions on the regime.

Beijing has reacted against U.S. deployments of missile defense systems, protesting strongly after the possibility surfaced earlier this year of the U.S. deploying an advanced missile defense system, known as Terminal High Altitude Area Defense (THAAD), to South Korea. (Yonhap)