Indiana Attorney General Greg Zoeller announced on Friday that he plans to file briefs in support of gay marriage bans when the Supreme Court takes up Proposition 8, California's marriage ban, and the federal Defense of Marriage Act (DOMA) next year.

“I'm not going to wait for people to challenge our statute,” Zoeller said during a year-end news conference. “There's a case that's going to go up before the Supreme Court, and I think it's my duty to file the amicus brief like we did with defending the roles of states in other areas.”

Zoeller filed a friend-of-the-court brief in August asking the high court to take the Prop 8 case and reverse a decision by the 9th U.S. Circuit Court of Appeals which found the 2008 voter-approved amendment to be unconstitutional.

“We contend the people of each state – either through their elected legislators or directly by referendum – should have the authority to define marriage within their state, and Indiana stands firm in its vigorous defense of each state's legal authority to recognize the traditional definition of marriage as a significant state interest,” Zoeller earlier said.

A proposed constitutional amendment limiting marriage to heterosexual couples in Indiana is expected to clear its final legislative hurdle early next year and make its way to the 2014 ballot.

(Related: Indiana: Majority oppose proposed gay marriage ban.)