The United States Veteran's Association of Samoa says it's been inundated with support for a petition calling for Cabinet Minister Han Joachim Keil to be allowed to leave the US.
The petition is to presented at the US Embassy in Samoa tomorrow.
The Association's president Mark Moors says it has helped organise the Free Joe march, to show support for Mr Keil, who many believe has been wrongfully detained in the US on immigration charges.
Mr Keil is under strict bail conditions in Missouri.
Mr Moors says thousands are expected to join friends and family wearing white for the march.
"I've been contacted by people from about 16 different organisations, quite a few charities, groups from the Samoa community here as well as from Joe's constitutency from the individual voters roll.'"
Mark Moors says they are supporting Mr Keil because he is a US military veteran.