As it gets increasingly difficult to obtain a work visa, more foreigners aren't able to come to the United States, and celebrities are no exception.

Sori Na, a South Korean dancer from 1MILLION Dance Studio, hailed for creating famous choreographies for top Korean pop artists and teaching public dance classes, was scheduled to visit five U.S. cities to hold dance workshops, starting at New York City's Ripley-Grier Studios on September 22.

But nine days before Na was supposed to hold her first workshop, the coordinators, KAMOFLAGE Entertainment, cancelled the event, citing that visa issues prevented her from entering the United States.

"For this travel, there were documentation issues with immigration," Jayden Kim, a representative of KAMOFLAGE Entertainment, said. "We are assessing the situation and speaking with her but no confirmed timelines at this time."

But Sori Na has been able to enter the U.S. before. In 2017, she held a dance class in Brooklyn and visited KCON NY in Newark. In 2018, she visited California and held a class in San Jose.

According to an analysis of USCIS data by the National Foundation for American Policy, denial rates for H-1B petitions have increased dramatically, rising from 6 percent in the 2015 fiscal year to 33 percent through the second quarter of the 2019 fiscal year. H-1B visas are one of the most common temporary work visas in the U.S.

"To put this in perspective, between FY 2010 and FY 2015, the denial rate of initial H-1B petitions never exceeded 8%, white today the rate is 4 times higher."

Last year, over 623,000 denials were issued.

Work visas can be denied for different issues including failure to provide proper documentation and if the job being applied for doesn't require specialized skills.

"Application and communication is a little more difficult nowadays," Frank Guerra, a Principal Attorney who specializes in family and business immigration, said. "Not everyone gets a fair shake sometimes."

A similar issue happened at this year's KCON, a Korean pop culture concert and convention. Some K-Pop artists, including EVERGLOW, Chung Ha and ONEUS, were promised to perform but because of visa issues, they were not able to enter the country to attend the sold-out shows in Madison Square Garden in New York and the STAPLES Center in Los Angeles.

Both coordinators, I Love Dance and KAMOFLAGE Entertainment, have apologized for the unexpected cancellation and fully refunded the people who bought tickets.

Bodhi Hwang, who was planning on attending the workshop, said, "I was disappointed when I first found out and was curious as to why the event was cancelled. I do wonder how the consulates decide on visas."

Kim from KAMOFLAGE Entertainment said they are trying to reschedule the class and plan more workshop tours with K-Pop choreographers in the future.

He said, "We are always working to get more South Korean choreographers to the U.S.."