Deposed Venezuelan leader Nicolas Maduro’s first appearance in a U.S. courtroom offered a glimpse of the legal battle ahead over rarely tested questions — chief among them whether he can claim immunity from prosecution.

Maduro, who pleaded not guilty to narco-terrorism and cocaine charges on Monday, defiantly claimed that he remained the president of Venezuela — setting up a showdown over the legal protections customarily given to heads of state.

His lawyer, Barry Pollack, signaled a second line of ?attack at the arraignment, promising voluminous litigation challenging what he called Saturday’s “abduction” by the U.S. military of Maduro and his wife.