Washington DC - US Secretary of State Marco Rubio vowed Tuesday not to let China erase the memory of the Tiananmen Square demonstrators crushed 36 years ago, in a rare return to human rights rhetoric.

The Chinese Communist Party (CCP) "actively tries to censor the facts, but the world will never forget," Rubio said in a statement.

"Today we commemorate the bravery of the Chinese people who were killed as they tried to exercise their fundamental freedoms, as well as those who continue to suffer persecution as they seek accountability and justice for the events of June 4, 1989," he said.

Rubio – during a long Senate career – was an outspoken advocate for human rights, especially in China, and spearheaded legislation imposing sanctions in response to the country's treatment of the mostly Muslim Uyghur minority.

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As President Donald Trump's top diplomat, Rubio has been more selective, focusing his rights criticism on US adversaries including China and Cuba.

In a restructuring of the US State Department, Rubio has gutted the office focused on human rights, which he accused of bias against Israel and Trump-aligned right-wing populists in Hungary, Poland, and Brazil. Trump made no public mention of rights during a business-oriented tour last month of energy-rich Gulf Arab monarchies.

Rubio's predecessors have issued statements each year to mark the anniversary of the bloody crackdown on pro-democracy protesters in central Beijing, an episode that China's rulers have sought to eliminate from public memory, especially online.

But Rubio's statement also had subtle differences – his Democratic predecessor Antony Blinken last year urged China to accept recommendations in a UN-backed rights review and to respect freedoms enshrined in the post-World War II Universal Declaration of Human Rights.

Rubio did not reference the United Nations, a frequent target of criticism by the Trump administration.

Instead, Rubio said that the Tiananmen protesters' "courage in the face of certain danger reminds us that the principles of freedom, democracy, and self-rule are not just American principles. They are human principles the CCP cannot erase."