US Secretary of State Rex Tillerson recalled the "violent suppression" of peaceful protests in and around the vast square in the heart of Beijing in a statement marking the 28th anniversary of the event.
The United States has routinely observed the anniversary with similar calls to China, but this was the first time under Trump's presidency.
"We call again on China to make a full accounting of those killed, detained or missing due to the events of June 4, 1989," he said.
"We urge China to cease harassment of family members seeking redress and to release from prison those who have been jailed for striving to keep the memory of Tiananmen Square alive.
"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 its citizens."
China responded to the student-led protests by declaring martial law and sending heavily armed troops and tanks into the square.
Hundred of unarmed civilians -- over 1,000 by some estimates -- are believed to have died in the crackdown.
Eyewitness? Submit your stories now via social or:
Email: news@pulselive.co.ke
