(CNN) — Her eyes teared up as a North Korean soldier gripped her hand in the hardest handshake she'd ever felt. "We're going to destroy you, America," he said.

Over the past year and a half, American traveler Cassie De Pecol has visited every country in the world, and the greetings she received weren't always gracious. She had set out to promote peace in her own small way, by meeting people from every country in the world -- and she did so at a record pace.

Traveling to all the world's 196 sovereign nations in 18 months and 26 days, De Pecol made the trip in less than half the time it took the previous Guinness World Record holder.

She recalled telling the North Korean guard about her mission: She was there to show that, even if their governments couldn't be friends, the two of them didn't have to be enemies. "I just like to show that we can be friends and we can kind of coexist," De Pecol said.

Cassie De Pecol in North Korea with her tour guide. She came to the country on a three-day organized tour with a Chinese tour group based out of Beijing. Cassie De Pecol

De Pecol, who majored in environmental studies in college, said she felt she couldn't travel the world without having a larger purpose. She embarked on her world tour in July 2015, promoting sustainable tourism everywhere she went as an ambassador for the International Institute of Peace Through Tourism.

The nonprofit was founded in 1986, the United Nation's "Year of Peace," to promote cultural understanding after terrorist incidents sparked tensions between Eastern and Western countries.

Over the course of her trip, she met with mayors and ministers of tourism, presenting them with the institute's " Declaration of Peace ." SKAL International, an association of tourism professionals with chapters all over the world, considered her a peace ambassador and helped De Pecol arrange meetings with dignitaries in more than 50 countries.

The 27-year-old spoke before more than 16,000 students about the ways to offset your carbon footprint when you travel.

Championing sustainability -- and being accused of hypocrisy

"If you say, fly from Bangalore, India, to Colombo, Sri Lanka, you end up killing one tree during that flight, the goal is to plant two trees, for regenerative tourism, not just sustainable tourism," De Pecol said.

Having flown over 255 times on her expedition, De Pecol says she's been called hypocritical for boasting a sustainable mission.

De Pecol aims to completely offset the heavy carbon footprint of her trip, however, planting trees in over 50 countries.

"It's tough to figure out to get permission to plant a tree in a lot of countries, but I've been trying to do that as much as possible. I've planted close to 50 trees now but there's about 500 more, so that's just a goal."

She said she would plant the rest when she gets back home to Connecticut after the expedition.

De Pecol said she's faced criticism for the short time she spent in each place -- too brief, critics say, to have meaningful experiences.

"It all comes down to two words: time management," De Pecol says in her defense. "One could spend Saturday and Sunday chilling at home watching Netflix -- totally OK, I am guilty of that at times -- or traveling to five places within one country, five countries within those two days."

Others accuse her of only being in it to chase the record -- and money.

How she funded the trip

In total, De Pecol budgeted $198,000 to get herself around the world.

De Pecol was 23 years old when she began planning her journey, and in the beginning she had no funding. During the year and a half that she spent planning her trip, she says she saved $10,000 by babysitting, then went about acquiring sponsors.

"I had to really utilize Google and be like 'how am I going to find the funding to do this?' 'How did other people find the funding to do this?' So I looked at people like Ranulph Fiennes who is considered the worlds greatest living explorer," De Pecol said.

She attracted a wide range of sponsors, from big companies like AIG to a hand-painted tote bag artisan, and she exchanged board at eco-hotels for promotional coverage of their sustainability efforts.

Before she embarked on her record-setting adventure, De Pecol had some practice traveling abroad on a budget. A semester shy of graduating at 21, she left college with a one-way ticket to Europe and $2,000. She spent two years traveling and working in hotels to satisfy her wanderlust.

Challenges she faced

Though Americans can travel freely in many parts of the world, obtaining visas for the countries that require them proved to be one of the biggest challenges, she said -- and geopolitical tensions came into play.

Travelers are not allowed to enter North Korea alone, and Americans who wish to visit are charged a hefty price.

"The visa was like $1,000 for three days, whereas I went in with a group of Chinese tourists and their visa was like $300 for three days," De Pecol said.

In other places where she struggled to get approved for a visa, like Turkmenistan and Syria, she turned to social media for help.

"There have been cases when I post on my Facebook 'Hi I need help getting into Libya' or 'I need help getting into Syria,' and at that point it's kind of trusting in the unknown, trusting in people," De Pecol said.

A statement for women's equality

Guinness World Records officials split the "fastest person to travel to all sovereign countries" into gender categories after another woman attempting the record said she couldn't get into Saudi Arabia without a male escort.

"When determining if a record will be separated by gender, we look at each record on a case by case basis to see whether or not the record poses a different challenge for each gender. This does not mean that one category is more challenging than the other, only that the challenge is different," said Kaitlin Holl, records manager for Guinness World Records.

Once evidence of her journey is validated by officials in the coming weeks, De Pecol will claim two titles -- both as the fastest female to travel to all sovereign countries and as the fastest person of any gender to make the trip. Michigan native Yili Liu has held the male record since 2010, completing the trip in three years and three months.

For De Pecol it was another mountain to climb for women's equality.

"I thought this is not right, this shouldn't be this way, and that's when I realized it was just one step backwards for equality between men and women, so I really made a push to bring that record back to where it was for the fastest person," De Pecol said.

To stay fit and healthy during her trip -- and to offset the times while traveling when she only had chips to eat -- De Pecol made sure to drink enough water, take vitamins and exercise.

She also went running wherever she was in the world, and practiced Krav Maga, an Israeli martial art she learned to be able to defend herself as a woman traveling alone. Krav Maga Worldwide was among her sponsors.

Her post-expedition body in top shape, she's scheduled to compete in an Ironman Challenge in San Diego this March.

What's next after visiting 196 countries

De Pecol said she may never put roots somewhere permanently, and isn't so sure about adopting the nine-to-five grind.

"I thought, you know what, it actually scares me a little bit. I would quit like after a week," she said.

There's just one place De Pecol hasn't been: Antarctica. While not technically a sovereign nation, she'll journey there with Quark Expeditions in late February.

"I was like, hey, if I go to six continents, 196 countries, I may as well hit up the last continent," De Pecol said.

She has plans to write a book about her journey and finish an educational documentary when she returns from Antarctica.