In the wake of widespread opposition to a number of recent decisions made by China, such as devaluing its currency, the United States has once again warned the nation. In recent weeks, U.S. President Barack Obama issued a warning to Beijing about the presence of covert agents on American soil, who are currently participating on a government-backed operation to send back expatriates suspected of criminal activity back to the mainland.

In a mission officially dubbed Operation Fox Hunt, the covert agents in the U.S. were tasked to hunt down and repatriate Chinese fugitives living abroad. In some cases, they are also assigned to recover ill-gotten wealth. Among the targets of Operation Fox Hunt are people suspected of corruption and political crimes as well, according to The New York Times.

Reports further state that the covert agents are operating under the guidance of China's Ministry of Public Security, and that the agents are entering American soil using tourist or trade visas.

The stern warning from the U.S. was directed primarily to the tactics used by the agents, which commonly include intimidation tactics and other forms of harassment, as well as direct threats to the welfare of their targets' family members in mainland China, reports BBC News.

More than 930 suspects have been repatriated to China since the program was commenced last year. Repercussions of the program, as well as the final decision about its operations in the U.S., may be among the issues to be discussed when Chinese President Xi Jinping arrives in the U.S. next month for a state visit.