Trump's new national security adviser is the hostage negotiator he sent to Sweden for A$AP Rocky's trial

Fredrik Persson/Reuters

US Special Presidential Envoy for Hostage Affairs Robert C. O'Brien arrives at the district court, during the third day of A$AP Rocky's trial, in Stockholm, Sweden August 2, 2019.

• President Donald Trump on Wednesday said he's planning to name Robert C. O'Brien as national security adviser.
• O'Brien has served as Trump's top hostage negotiator, and recently made headlines when he was sent to Sweden to monitor rapper A$AP Rocky's trial.
• Trump abruptly dismissed John Bolton as national security adviser last Tuesday, and O'Brien will take over amid a crisis with Iran. 
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President Donald Trump on Wednesday announced Robert C. O'Brien, his top hostage negotiator, will be the administration's new national security adviser.

Trump announced the news in a 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!"

O'Brien made headlines over the summer after Trump sent him to Sweden amid rapper A$AP Rocky's trial for assault charges. It was an unusual assignment given a diplomats like O'Brien typically handle hostage situations in war-torn countries, and he was asked to go to Sweden to monitor a rapper's assault trial and put pressure on the Swedish government.

Trump dismissed John Bolton as national security adviser last Tuesday, and O'Brien will take over amid a crisis with Iran. 

O'Brien will be Trump's fourth national security adviser, assuming a top role in a chaotic White House typified by high rates of turnover.