Chinese leaders must “make a full public accounting” of the 1989 crackdown on protestors in Tiananmen Square, Secretary of State Mike Pompeo said Sunday.

“On the 29th anniversary of the violent suppression of peaceful demonstrations in and around Tiananmen Square on June 4, 1989, we remember the tragic loss of innocent lives,” Pompeo said. “As Liu Xiaobo wrote in his 2010 Nobel Peace Prize speech, delivered in absentia, ‘the ghosts of June 4th have not yet been laid to rest.’”

That statement in memoriam is a two-pronged rebuke of the Chinese Communist regime. Liu died in Chinese custody last year after nearly three-decades of political opposition, a career that began with a hunger strike in solidarity with the Tiananmen Square protestors in 1989. Chinese censors work aggressively to censor any mention of the suppressed protests around the time of the anniversary.

“We join others in the international community in urging the Chinese government to make a full public accounting of those killed, detained or missing; to release those who have been jailed for striving to keep the memory of Tiananmen Square alive; and to end the continued harassment of demonstration participants and their families,” Pompeo said.

To the contrary, the Chinese government has ramped up its efforts to censor criticism of the Communist Party, to autocrat Xi Jinping, and any references to Tiananmen Square. “We had about 30-40 employees two years ago; now we have nearly a thousand reviewing and auditing,” one censor told Reuters in September.

Liu’s wife, Xia, lives in Beijing. “They are going to keep me here to serve out Xiaobo’s sentence,” she told a friend in a recorded phone call published last week. “I want to see just how much more cruel they can get and how much more shameless they will become; I want to see how much more depraved this world is.”

The anniversary coincides with the run-up to a high-stakes summit between President Trump and North Korean dictator Kim Jong Un, whose regime long has been a client of its larger Communist neighbor. China also has deployed military assets to artificial islands in the South China Sea to bolster its claim to sovereignty over one of the most vital shipping lanes in the world.

“The United States views the protection of human rights as a fundamental duty of all countries, and we urge the Chinese government to respect the universal rights and fundamental freedoms of all citizens,” Pompeo said.