Updated at 2:31 p.m. ET
President Trump has named Robert C. O'Brien, who has been his special envoy for hostage affairs, to be his new national security adviser.
Trump made the announcement in a Wednesday morning tweet.
"I am pleased to announce that I will name Robert C. O'Brien, currently serving as the very successful Special Presidential Envoy for Hostage Affairs at the State Department, as our new National Security Advisor. I have worked long & hard with Robert. He will do a great job!" Trump said.