Nielsen was former DHS Secretary John Kelly's deputy when he served in that role and moved with Kelly to the White House when he was tapped to be Trump's chief of staff.
"A state that has developed a pretty good ICBM (missile) capability and is developing a pretty good nuclear re-entry vehicle, I would believe ... that that state simply can not have the ability to reach the homeland", Kelly said. "I don't believe - and I just talked to the president - I don't believe that I'm being fired today".
Kelly took issue with the notion that he is a "failure" for not controlling Trump's frequent tweeting, which has not stopped during his tenure as chief of staff. "His sense as a man who is outside the Washington arena, a businessman, much more of a man of action, I would say his great frustration is the process he now finds himself [in] because, in his view, the solutions are obvious".
"I hope he shamed a few people today into thinking twice about where they are getting their information", Conway said.
But on Thursday he was in a humorous mood and said: "You guys with the cameras always catch me when I'm thinking hard, and it looks like I'm frustrated and mad". He said the North has developed a "pretty good" intercontinental ballistic missile capability and is developing a nuclear re-entry vehicle, which is needed for a missile to survive re-entry into the Earth's atmosphere.
When asked what frustrates the president, Kelly laughed and said he thought that it was the media. "But I listen to everybody and ultimately I will do what's right for the United States and really what's right for the world", he said, adding, "it's a problem that has to be solved". The best job I've ever had, as I've said many times, is when I was an enlisted marine sergeant infantryman. Kelly was elevated to the post from homeland security secretary in July.
In a statement, Senator Ron Johnson said, "Ms. Nielsen's long history of service with the Department, her cybersecurity experience and her tenure serving with General John Kelly would serve her well as the next Secretary of the Department of Homeland Security".