Barack Obama is speaking out against the invasion of Ukraine by Russian military groups. In a lengthy post found on his Twitter and Instagram accounts, the former president denounced the attack. He said it was a “violation of international law and basic principles of human decency” and claimed that the move not only threatens Ukraine but “the foundation of the international order and security.”

He also called on people to condemn the Russians for their “reckless actions” and asked Americans to support Joe Biden’s newly-imposed sanctions.

“People of conscience around the world need to loudly and clearly condemn Russia’s actions and offer support for the Ukrainian people. And every American, regardless of party, should support President Biden’s efforts, in coordination with our closest allies, to impose hard-hitting sanctions on Russia — sanctions that impose a real price on Russia’s autocratic elites,” Obama wrote.

“There may be some economic consequences to such sanctions, given Russia’s significant role in world energy markets. But that’s a price would be willing to pay to take a stand on the side of freedom,” he continued. “For over the long term, we all face a choice, between a world in which might makes right and autocrats are free to impose their will through force, or a world in which free people everywhere have the power to determine their own future.”

After several warnings over the weeks, Biden imposed sanctions that target four Russian banks, “corrupt billionaires” and their families and more. The sanctions are the U.S.’ response to explosions in Ukraine and Russia’s seizure of Chernobyl and the Antonov International Airport.

Look below to read the full post from Barack Obama. He’s sending his prayers to the “courageous people of Ukraine,” Russian citizens who were against the attack and those “who will bear the cost of a senseless war.”