TheU.S. citizens from traveling to North Korea after the .
Last week, his father lashed out at tour companies that arrange trips to the isolated country, reports CBS News correspondent Ben Tracy.
"The North Koreans lure Americans to travel to North Korea via tour groups run out of China who advertise slick ads on the internet," Fred Warmbier said.
Democratic Congressman Adam Schiff introduced a bill to prohibit all American tourist travel to North Korea and has called the country a "despotic regime."
"Americans go there, they're often taken hostage, essentially, and the North uses them as bargaining chips," Schiff said.
The State Department says at least 16 Americans have been detained by North Korea in the last 10 years. A travel warning is already in place.
The tour group that arranged Warmbier's trip is based in China. It says his death prompted them to stop bringing U.S. citizens to North Korea because it is too risky.
Another travel company CBS News spoke to says they're taking a look at their policies, but for now, Americans are still welcome.
Warmbier, a 22-year-old college student, was arrested in the country last year for allegedly stealing a propaganda poster from his hotel. He was in a coma when he was released last week and died in Ohio Monday.
Before his arrest, Warmbier seemed to be having a good time in North Korea. Newly-released pictures show him smiling with his tour group, posing in front of statues of the country's leaders and sampling North Korean food.
But after Warmbier's death, the company that booked his visit -- Young Pioneer Tours -- said U.S. citizens will no longer be allowed on their trips.
In a statement the company said, "The assessment of risk for Americans visiting North Korea has become too high."
Uri Tours, which has arranged trips for more than 2,000 U.S. citizens, told "CBS This Morning": "We're reviewing our policies on Americans traveling to [North Korea]."
"I was extremely excited about the opportunity to go and capture images," said Tyson Wheatley, a photographer who traveled to North Korea one month after Warmbier received a 15-year prison sentence. Wheatley traveled with a tour group and says he knew the risks but wanted to visit one of the most mysterious places on earth.
"As an American, I feel extremely fortunate that we are able to travel around the world. But I don't think it's the government's role to tell us where we can and cannot go," Wheatley said.
Wheatley said his tour group was explicitly told not to take pictures of construction and not to fold up or throw away a newspaper that had Kim Jong Un's picture on it.
Reporting from North Korea in April, the CBS News team stayed at the same hotel where Warmbier allegedly tore down that propaganda poster.
Tourists from around the world that Tracy met in North Korea told him they came there because they were simply curious. They wanted to see one of the places in the world few people ever visit.
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