WASHINGTON: A Chinese-born American seismologist who has published US-funded work on detecting North Korean nuclear tests has been detained in China for nearly two years and faces trial on spying charges, according to his wife, US lawmakers and two hostage advocacy groups. The case of Youlin Chen, reported here for the first time, ​adds an irritant to the tense relationship between the nuclear-armed rivals and comes as President Donald Trump seeks to keep the relationship steady following last year’s trade war.

Secretary of State Marco Rubio on March 19 designated Chen, 54, as “wrongfully detained,” making his release a top US priority. The Trump administration has withheld a public announcement to allow space for high-level diplomacy aimed at securing his freedom, according to his wife, Yufang Rong.

Dr. Yufang Rong and her husband Dr. Youlin Chen, an American seismologist held for nearly two years by China, pose together in this undated photograph provided on July 13, 2026. (REUTERS)

A US source familiar with Chen’s case said the administration was “focused on gaining his release from his unjustifiable detention.” The source spoke on condition of anonymity to discuss sensitive diplomatic talks.