The State Department called on China to release a US citizen on Thursday who it says was wrongfully detained on espionage charges.

Min Zin, an academic who leads a think-tank focused on Myanmar, was detained by Beijing on June 3 after it extended him an invitation to attend an academic conference along the border in Yunnan.

“Secretary Rubio has formally designated US citizen Min Zin as wrongfully detained,” Dylan Johnson, the assistant secretary of state for global public affairs, wrote on X.

“We call on Beijing to release all U.S. citizens arbitrarily detained or exit banned in China,” he added. “The safety and security of U.S. citizens is the State Department’s top priority.”

Zin is a PhD candidate in political science at the University of California, Berkeley, with the American founding the Institute for Strategy and Policy (ISP) — Myanmar in 2016.

The academic was a former student activist in Myanmar’s pro-democracy movement in 1988, with democratization being the focus of his studies, according to his think tank.

The ISP was tracking the status and failings of Myanmar’s government, which came to power following a military-engineered election, with the new administration receiving China’s public backing.

Zin was arrested after flying into Kunming, in southwest China, where the American national was accused of spying and endangering Chinese national security.

The ISP denied the allegations and pleaded with the State Department to help free their founder as President Trump prepares to meet China’s Xi Jinping in September.

“We humbly ask that the US government continues to keep Min Zin’s case as a top priority, particularly ahead of President Xi’s visit to meet with President Trump next month, and that the People’s Republic of China (PRC) facilitate his immediate and unconditional release,” the ISP said in a statement.

Zin is one of two US citizens being wrongfully detained by China, according to the State Department.

Youlin Chen, a seismologist who studied North Korean nuclear tests, was arrested at Beijing International Airport while trying to fly home to Boston, with China also accusing him of spy charges.