Former US presidents Bill Clinton, and George W. Bush, laid flowers outside a Ukrainian church in Chicago in a show of support for the Ukrainian people.
"America stands united with the people of Ukraine in their fight for freedom and against oppression," Clinton wrote on Twitter.
It is a message echoed on the Twitter handle of Bush's foundation.
The two men from different political parties also wore ribbons with the colors of Ukraine's flag.
They said the initiative aimed to show their solidarity with the people of Ukraine.
Earlier in the conflict, former President Barack Obama slammed Russia's "brazen attack" on Ukraine. He has posted several messages on social media directing people to help Ukrainians through ordinary organizations deployed on the ground, DW reports.
