Former U.S. President Barack Obama, who championed engagement with Myanmar’s military while in office to promote democratic change, said on Monday he was “appalled by heartbreaking violence” it had used against civilians after retaking power in a coup. In a rare statement, Obama said he supported efforts by the Biden administration and like-minded countries to impose costs on Myanmar"s generals. "The military’s illegitimate and brutal effort to impose its will after a decade of greater freedoms will clearly never be accepted by the people and should not be accepted by the wider world," Obama said in the statement posted on Twitter. "Myanmar’s neighbors should recognize that a murderous regime rejected by the people will only bring greater instability, humanitarian crisis, and the risk of a failed state," he added. Obama urged those in Myanmar who sought a democratic future to "continue to forge solidarity across ethnic and religious groups." "These are dark times, but I have been moved by the unity, resilience, and commitment to democratic values demonstrated by so many Burmese, which offers hope for the kind of future Myanmar can have through leaders who respect the will of the people," the former president said. An activist monitoring group has said more than 750 people have been killed since the generals unleashed lethal force against those protesting their Feb. 1 coup. loading It has been a major turnaround from the high hopes of a decade ago, when the military initiated a transition toward democracy. Then, the generals released democracy leader Aung San Suu Kyi and allowed her to run for office and opened energy and telecoms tenders to foreign companies. Obama responded by lifting a trade embargo and most sanctions, moves some U.S. officials thought premature. Many of the sanctions have been reimposed since the coup. The Assistance Association for Political Prisoners advocacy group said 3,431 people have been detained for opposing the coup, including Suu Kyi, who faces charges that could see her jailed for 14 years.