But it is not just the economic downturn and visa issues that are keeping foreigners from working in the United States.
Educators say opportunities abroad, specifically in Asia, also are luring both foreigners and U.S. citizens.
It's all about relative opportunity, said Ron Hira, a professor at Rochester Institute of Technology and author of "Outsourcing America: The True Cost of Shipping Jobs Overseas and What Can Be Done About It."
"Opportunities in India and China are much better than they were a generation or 10 years ago, which is attracting a number of people to go back," he added. "The new term that's being used is 'brain circulation' -- that people are moving back and forth."
The loss of foreign nationals has both advantages and disadvantages. The United States may lose some of its brightest, but that may open up more opportunities for U.S. citizens, Hira said.
The issue of visas is not a new one, but the current economic conditions are bringing it to the forefront. When foreign nationals who are on a work visa lose their job, they have no choice but to leave the country.
The Duke University study found that more than 1.1 million skilled workers were waiting for green cards in 2006, and it can take anywhere between six to 12 years to get one.
Foreign workers can only apply to companies that can sponsor their visas. In the current climate, that may be a difficult task, and even those whose jobs are secure may have to contend with lesser promotions and lower salaries.
"You [particularly foreign students] have to sell yourself extra hard in a competitive market like right now," said John Landers, a regional manager at recruitment firm Robert Half International. "I think some people are starting to get a little bit desperate just because there are not many opportunities out there."
International students attending U.S. universities can work in the country for a year after their graduation, after which they must obtain a temporary work visa known as H1-B, which is applicable for six years.
There are 65,000 H1-B visas available for those who hold an undergraduate degree, and 20,000 additional ones for those with a masters degree.
H1-B visas are in short supply -- the cap on applications for H1-B visas was reached on the first day they were available for fiscal year 2008.
A 28-year-old Japanese engineer, who did not want his name to be revealed, said he was facing a tough decision between moving back to Japan or staying in an unchallenging job in the United States.
"It's hard for me to find a job in the U.S.," he said. "The economy is going down and I have been contacted with a couple of agencies, but almost everybody said it's too hard for us to look for a job."
Foreign workers like him and students like Lekharaju are hoping more opportunities will emerge in the near future, especially after the new administration takes office. But it remains to be seen whether the government will expand H1-B visas to attract more foreign talent.
"What was a trickle will become a flood, and I see the U.S. now having to accept a new reality," said Wadhwa. "In the past, we would take it for granted that the world's best and brightest come here. Now we will have to complete with them, just like Europe and the Middle East does."