President-elect Donald Trump on Monday officially announced he plans to nominate retired Marine Corps Gen. John Kelly to be the next secretary of the Department of Homeland Security.

“Gen. John Kelly’s decades of military service and deep commitment to fighting the threat of terrorism inside our borders makes him the ideal choice to serve as our secretary of the Department of Homeland Security,” Mr. Trump said.

Gen. Kelly said he is “humbled and grateful” to be nominated to serve in the post.

“The American people voted in this election to stop terrorism, take back sovereignty at our borders and put a stop to political correctness that for too long has dictated our approach to national security,” Gen. Kelly said. “I will tackle those issues with a seriousness of purpose and a deep respect for our laws and Constitution.”

Gen. Kelly is the former head of Southern Command, the military post that oversees U.S. activities in Central and South America. He has testified to Congress about the security threat posed by a porous U.S.-Mexico border.