Scott Walker filed paperwork with the Federal Election Commission Thursday to formally become a candidate for the GOP nomination in 2016, aides to the Wisconsin governor confirm to NBC News.
Walker had already indicated that he is planning a formal announcement on Monday, July 13. That event is slated to take place in Waukesha, Wis.
He will be the 15th Republican to jump into the presidential race. Another fellow GOP governor, New Jersey's Chris Christie, announced his White House run on Tuesday.
Walker, who has earned accolades from conservatives for his fights against unions in Wisconsin, led a recent poll of likely caucus-goers in the key state of Iowa. He's considered a top-tier candidate for the Republican nomination.
The news of Walker's FEC filing was first reported by POLITICO.