U.S. Secretary of State Mike Pompeo has urged China to disclose the details of people killed, detained or missing during the Chinese military’s crackdown on pro-democracy protesters centered on Beijing’s Tiananmen Square 29 years ago.

Pompeo marked Monday’s anniversary of the suppression of demonstrations on June 4, 1989, saying: “We remember the tragic loss of innocent lives.”

“We join others in the international community in urging the Chinese government to make a full public accounting of those killed, detained or missing,” Pompeo’s statement said.