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As President Trump and North Korea launch threats at one another, inching closer toward taking military options that could lead to a catastrophic war, an expert said there are few options to dissolve the crisis in the Korean Peninsula.

“We don’t have a lot of good options, I’m afraid to say,” former CIA analyst Sue Mi Terry told “Fox & Friends Sunday.”

North Korea’s foreign minister, Ri Yong Ho, lambasted Trump on Saturday, calling him “a mentally deranged person full of megalomania” after the U.S. president mocked Kim Jong Un and threatened to “totally destroy North Korea” during his Tuesday address to the United Nations General Assembly. Terry said North Korea didn’t expect this level of rhetoric from the U.S.

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North Korea's foreign minister Ri Yong Ho called President Trump "a mentally deranged person full of megalomania" on Saturday. (AP)

“My only concern is, it’s going to escalate because North Koreans can’t back down either. Kim Jong Un has spent on completing his nuclear program. [North Korean officials] said they have to perfect their degree of arsenal to achieve their ultimate capability to attack mainland United States with intercontinental ballistic missiles. And now, they will have to react too,” Terry said.

TRUMP ON NORTH KOREA, FROM 'ROCKET MAN' TO 'FIRE AND FURY'

North Korea was “riled” up before, when former President George W. Bush called the Hermit Kingdom part of the “axis of evil.” The former CIA analyst predicts North Korea will respond to Trump’s threats with another nuclear test or ICBM launch.

However, Terry said she still believes the bombastic threats won’t lead to military action.

“The military option would mean massive casualties,” Terry said. “I just don’t see how we can avoid a big conflict on the Korean peninsula just because North Korea is really a nuclear power that puts Japan and South Korea under nuclear threat.”

Terry said if the U.S. does choose to attack North Korea, Kim Jong Un will retaliate, threatening to cause major damage to neighboring countries.

“Of course at the end, North Korea will be devastated and utterly be destroyed in an all-out conflict. And Japan will particularly take a big hit,” Terry added.

She said an attempt to topple Kim Jong Un’s regime would be a “difficult option to pursue” because North Korea is one of the “most isolated countries on the face of this Earth.”

TRUMP: NORTH KOREAN LEADERS 'WON'T BE AROUND MUCH LONGER' IF THEY STRIKE US

Trump continued to mock Kim as the “little rocket man” in a tweet Saturday night and warned the rogue regime “won’t be around much longer” if it strikes the U.S. Ri promised a strike on the U.S. mainland was “inevitable.” Kim responded to Trump’s U.N. General Assembly speech on Friday by calling Trump a “mentally deranged U.S. dotard” and vowing the U.S. would “pay dearly” for threatening to destroy his regime.

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The Pentagon said B-1B bombers from Guam and F-15 fighter escorts from Okinawa, Japan, flew a mission in international airspace over the waters east of North Korea. (AP)

In a show of force, B-1B bombers from Guam and F-15 fighter escorts from Okinawa, Japan, partook in a mission in international airspace over the waters east of North Korea Saturday, the Pentagon said.

Defense Department spokesperson Dana White said in a statement that the mission shows how seriously the U.S. takes what she calls North Korea's "reckless behavior."

The flights are a "demonstration of U.S. resolve and a clear message" that President Trump "has many military options to defeat any threat,” White said.

The Associated Press contributed to this report.