Former Trump administration official Dr. Sebastian Gorka is urging the president to take decisive action against Obama administration officials involved in conducting surveillance on the Trump campaign and to release as much information on those efforts as possible.

Gorka, also the author of the forthcoming book "Why We Fight: Recovering America's Will to Win," is also applauding President Trump's decision to cancel the summit with North Korea and believes this shows exactly what kind of a leader Trump is.

Recent, widespread reports indicate that the FBI enlisted an informant to make contact with Trump campaign officials in an effort to investigate – or instigate, as Trump alleges – the connection between the Trump campaign and Russian efforts to meddle in the 2016 campaign.

"It's the worst political scandal in American history. What we have is one administration deciding that they can spy on another presidential candidate and his campaign for purely political reasons. For more than a year, people laughed when the president said, 'I was surveilled.' Now we know that not only was he surveilled, they put covert assets into his campaign," said Gorka.

Gorka says Trump needs to respond boldly.

"Right now all the key personnel from the last administration must be stripped of their security clearances. The idea that (former CIA Director) John Brennan is feeding Russian propaganda lines on national television and still has his security clearance is absurd," said Gorka.

He says security clearances should also be revoked for others involved in Operation Crossfire Hurricane, including former Director of National Intelligence James Clapper, former FBI Director James Comey and 2016 Democratic nominee Hillary Clinton.

Gorka says transparency should also be on Trump's short list.

"Now we have to see every document associated with Operation Crossfire Hurricane, the illegal political espionage operation authorized by the Obama administration. All those documents must be declassified and the president can do that at the stroke of a pen," said Gorka.

Gorka is also pleased to see Trump back away from the scheduled June 12 summit with North Korea's Kim Jong-Un. In a letter to Kim, Trump said he was canceling the meeting because of North Korea's "openly hostile" language in recent statements.

"North Korea has everything to lose. We have nothing to lose," said Gorka, who says this episode exhibits the same leadership and negotiation skills that Gorka saw during his time at the White House.

"You see a man who is decisive. He knows what he wants. He's results oriented. He cares about this country. He's a pragmatist and a patriot," said Gorka.

Gorka says Trump's move to scrap the summit should come as no surprise to anyone who read Trump's book, "The Art of the Deal."

"In chapter two, he states unequivocally (to) never, ever be so wedded to any deal so that you can't walk away at any point. That's exactly what the president did.

"This is a man who isn't interested in empty pablum or nice pieces of paper to wave at you. He isn't an individual who looks at the world through ideological filters. He wants results. When he doesn't get them, he'll walk away," said Gorka.

So what happens next in the effort to rid North Korea of nuclear weapons? Gorka says China will play a key role in determining just how badly the U.S.-led sanctions strain the Kim regime financially and possibly lead to an even better deal.

He also believes the days of the Kim regime are numbered.

"This is the great paradox of all dictatorships. They're very powerful at the top. They deny individual liberties. But at the end of the day, they're also highly vulnerable because of the denial of human of liberty that they are founded upon. So this is not a regime that can last forever," said Gorka.

While crippling economic sanctions and a robust military brought North Korea to the brink of denuclearization, Gorka believes the same results will be more difficult to achieve with Iran due to the Islamist mindset of its leaders.

"At the end of the day, the North Korean dictatorship is evil but they're rational. When you're dealing with a theocracy like Iran, there are individuals at the top, amongst the mullahs, who do not think in rational terms. Several of them believe in the occultation of the 'Hidden Imam' and actually think ideas like apocalypse are a good thing.

"The question in Iran is who is in ascendance, the less rational individuals or the more rational individuals? If it's the latter, then we can probably see some positive results coming out of Tehran as well," said Gorka.