Tiananmen Mothers condemn China's President Xi Jinping "To this day, all our efforts have been in vain, we have received not a single response from the government," said the letter, posted on an overseas rights group's website ahead of the 24th anniversary of the crackdown on June 4. China's government has so far provided no official toll for the repression, which was condemned throughout the world and led to the temporary isolation of Beijing on the international stage. Unofficial estimates of the numbers killed range from around 200 to more than 3,000. The Tiananmen Mothers said in the letter they believed the higher figure was accurate. Analysts say any official reassessment of the protests would be a key signal that Chinese leaders were willing to contemplate reform of the country's political system, which has been largely unchanged since the protests. China's government maintains that the huge growth of the country's economy in recent decades has justified its authoritarian political model. "We can see that the path we have chosen serves the fundamental interest of the Chinese people," foreign ministry spokesman Hong Lei said in response to a question about the letter on Friday. The Chinese people enjoy extensive rights and freedom. The Tiananmen Mothers group said last year that one of its members, the father of a 22-year-old man killed by soldiers during the crackdown, had committed suicide, leaving a note that detailed his continued distress over the killing. "We will never give up, never stop, until June Fourth is finally reassessed, and the souls of the victims rest in peace," the letter said.