This thesis analyzed the United States response to the enhansement in China – Russian military cooperation in Xi Jinping era. The increasingly intense military cooperation between China and Russia received a response from the United States government. This is because the niliter activity of the cooperation between the two countries focused in the Asia-Pacific region directly triggered the U.S. concern at this time. In analyzing against the United States response, this thesis uses the theory of neorealism as the basis for analysing it is equipped with several concepts such as foreign politics, balance of power and security's dilemma. The method of writing used is qualitative by using the techniques of collecting some data with the study of libraries. The Data obtained comes from several scientific papers, journals, articles, books, government documents, and online media websites. Once the data is collected it is then processed and represented into a written exposure. Based on the results of this study, there were some United States responses to the increase in China's military cooperation with Russia. Among other bilateral reinforcement with allied countries in the Asia- Pacific region. In addition, it increases military budget as well as military capabilities and Military Strategy.