Trump names US hostage negotiator O'Brien as his new national security adviser

President Donald Trump on Wednesday announced that he was naming U.S. hostage negotiator Robert O'Brien as his new national security adviser, replacing John Bolton who left abruptly last week after long disagreements with Trump and his other advisers over Iran, North Korea and Afghanistan.

"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," Trump tweeted while traveling in California. "I have worked long and hard with Robert. He will do a great job!"

O'Brien, the former Special Presidential Envoy for Hostage Affairs at the State Department, will replace John Bolton, who the president said he dismissed on Sept. 10. while Bolton said he resigned.

At the State Department, O'Brien worked closely with Secretary of State Mike Pompeo on the release of hostages including Pastor Andrew Brunson from Turkey and was also sent to Sweden to negotiate the release of detained musician A$AP Rocky -- a case the president took particular interest in.

The president praised his decision to appoint O'Brien, the fourth national security adviser of his administration, as "fantastic." Trump stepped off Marine One at the airport in Los Angeles with O'Brien at his side and introduced him to reporters traveling with the president.

"Mister O'Brien is highly respected," the president said. "He did a tremendous job on hostage negotiation. We've had tremendous success in that regard," adding "through hostage negotiations I got to know him very well. We have a very good chemistry together and I think we're going to have a great relationship."

O'Brien said "it's a privilege" to serve and he looks forward to another "year and a half of peace through strength."

"We've had tremendous foreign policy successes under President Trump's leadership and I expect those to continue," O'Brien said.

The new national security adviser steps into the role with a full plate of pressing foreign policy challenges, foremost Iran. When asked what kind of advice he plans to give the president on the attack on oil facilities in Saudi Arabia, O'Brien said he is still monitoring the situation and would not share any counsel he plans to give the president.

While he was special envoy for hostage affairs, O'Brien also worked as a Republican lawyer in Washington where he maintained a portfolio of "commercial litigation matters and international arbitrations," according to his law firm's website. His biography states that he served as a legal officer at the UN Security Council in Geneva, Switzerland, was a Major in the US Army Reserve JAG Corps, and served as foreign policy adviser on three presidential campaigns.

O'Brien was one of many candidates the president on Tuesday said he was considering for the position, including Ric Waddell, Lisa E. Gordon-Hagerty, Fred Fleitz and Keith Kellogg.

While aboard Air Force One with reporters yesterday, the president, who had criticized Bolton as "Mr. Tough Guy," singled out O'Brien for praise.

"Robert O'Brien said Trump is the greatest hostage negotiator in history. He happens to be right. We are 38-0. 38-0, ask Robert. In fact, I had never heard the term. Robert O'Brien said Donald Trump is the greatest hostage negotiator of all time. 38-0. At the time he said it we were 29-0. We are 38-0….” Trump said.