FILE PHOTO: U.S. Republican presidential candidate Marco Rubio speaks at a campaign event in Coralville, Iowa, United States, January 18, 2016. REUTERS/Jim Young/File Photo

BEIJING (Reuters) -The United States, in its commemoration of the Tiananmen protests in 1989, "distorted" historical facts and attacked China's political system, the Chinese foreign ministry said on Wednesday.

China has lodged a complaint to the U.S. side, Lin Jian, spokesperson at the Chinese ministry, said at a regular news conference.

Chinese tanks rolled into the square on June 4, 1989, and troops opened fire to end pro-democracy demonstrations. The Communist Party has never released a death toll, though rights groups and witnesses say the figure could run into the thousands.

"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," U.S. Secretary of State Marco Rubio said on Tuesday.

"The CCP actively tries to censor the facts, but the world will never forget," he said.

(Reporting by Ryan Woo; Editing by Himani Sarkar)