President Donald Trump’s deputy national security adviser, K.T. McFarland, told Business Insider that she told federal officials to abandon the “mush” of past US policy concerning North Korea, in favour of an “outside the box” approach.

A former aide on the National Security Council under presidents Richard Nixon and Gerald Ford, McFarland said that her efforts resulted in a set of policy and military options that “we didn’t realise we might have had.”

But McFarland said she had to push government officials to abandon the positions the US has taken for decades. She was disappointed with the initial options she was presented with.

“They came back with the same old mush, which was a little bit of policy, a little bit of sanctions, a little bit of diplomacy,” McFarland said. “And I said, after they came back with this, ‘This is what we’ve been doing for 20 years, none of this works.'”

So McFarland said she told representatives from the Departments of Defence, State, Justice, Commerce, and Treasury, as well as members of the military and intelligence communities, to “go back and talk to the people in the bowels of your building and come back with some really creative ideas.”

“There is nothing that’s off the table, and think outside the box,” she added.

In recent months, the Trump administration has sent mixed signals on North Korea, at times taking a more aggressive stance than its predecessors, threatening to use military force against the country and leverage America’s trade relationship with China to pressure it to act against North Korea. At other points, administration officials have said they are putting pressure on the country to enter into dialogue with the US and its allies.

National security policy under Trump, more broadly, has been in flux, in part due to staff changes on the NSC.

In February, Gen. H.R. McMaster, a widely respected Army general and military strategist, took over as national security adviser from Lt. Gen. Michael Flynn, who was forced to resign following reports that he misrepresented conversations he had with the Russian ambassador to Vice President Mike Pence.

Shortly after McMaster took over, he reorganized the NSC, pushing out Trump’s chief strategist, Steve Bannon, and elevating traditional members of the committee who had been demoted by Trump, including the Joint Chiefs chairman, director of national intelligence, and CIA director.

And Bloomberg reported last month that McMaster has forced McFarland off of the NSC. The president will likely nominate her to be US ambassador to Singapore in the coming weeks.

McFarland reportedly frustrated some officials on the council, which considers itself apolitical, for partisan comments she made in meetings. A frequent Fox News contributor, McFarland had been out of government for over 30 years when she joined the Trump administration.

Politico reported earlier this month that Gen. Ricky Waddell will replace McFarland.

While McFarland could not confirm that she will be nominated for the ambassadorship, she told Business Insider that her new position would involve national security policy in the Pacific and that she would “have to pack my bags and move overseas to take the job.”

“I’m very excited at the role that I’m going to be able to play in a part of the world that I think we’ve not paid enough attention to for the last 15 years,” McFarland said. “I think we’ve been focused on the Middle East when the real change, the real opportunities for commerce, diplomacy, et cetera are going to be in the Pacific.”

McFarland framed the reassignment as a voluntary “promotion,” which came after the president asked her whether she would rather remain in the White House or be moved elsewhere.

“I can tell you that I have had a number of conversations with the president in the last two months about what my role would be and he’s offered several things,” McFarland said. “He’s asked me a couple of times, ‘Gee, what would be better — staying in the job you have now or something else?’ And we’re determined that it’s something else.”

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