Natalie Portman and her fiancé Benjamin Millepied have joined other celebrities in signing Freedom to Marry's "I Do" open letter calling on President Barack Obama to support gay marriage.
"Natalie Portman and her fiancé, Benjamin Millepied, are in love, and believe all loving couples should be able to share in the freedom to marry without discrimination," Freedom to Marry president Evan Wolfson said in a statement.
The campaign launched in March and more than 100,000 people have signed on.
The letter calls for "clarity from the President" and urges him to "join us and the majority of Americans who support the freedom to marry," the group said. Read the full text of the letter.
Other celebrities who have joined the campaign include Anne Hathaway, Jane Lynch, Eric McCormack, Martin Sheen, Ellen Degeneres, Mya and LeAnn Rimes.