Clad only in a back-baring undergarment and trousers, the 54-year-old turned her back on the audience to show off the new temporary inking on her body, reported Daily Mail.
Madonna is a supporter of President Obama.
The mother-of-four was recently blasted by Russia's deputy prime minister after she supported jailed rockers Pussy Riot by scrawling their name on her back at her concert last month.
