The number of people moving into the Twin Cities from abroad fell dramatically over the last two years, based on new Census estimates that show the effect of shifting federal immigration policies.

The number of international migrants was about a third lower in 2017 and 2018 than it was in the preceding years — a drop of more than 4,000 people. The change was revealed in 2018 population estimates released this week by the U.S. Census Bureau, which also for the first time showed the substantial decrease in 2017.

Experts say the data reflects one of the first glimpses of the demographic shifts caused by tighter immigration rules, which affect highly skilled workers, refugees and people trying to rejoin family members in Minnesota.

Michelle Rivero, the director of Minneapolis' Office of Immigrant and Refugee Affairs, said a number of factors likely contributed to the change. It is taking longer for people to obtain visas — which are also being denied more often — the country is accepting fewer refugees, and the Trump administration's travel ban has complicated family-based immigration.

"Those [changes] may seem invisible to people," Rivero said. "The true measure of the impact of these changes in policies is borne out by these numbers."

The migration shift coincides with a drop-off in refugees arriving to the state, which fell from about 3,000 in 2016 to 663 in 2018, according to the ­Minnesota Department of Human Services.

The 16-county Twin Cities metro area, as defined by the U.S. Census Bureau, grew by about 1% last year — about the same as the year before. There were just over 8,000 international migrants, compared with more than 12,000 in the years between 2014 and 2017. That includes anyone who moved there from abroad, even expatriates returning home.

State demographer Susan Brower said an aging population in the metro area means the area needs newcomers from abroad and elsewhere in the country.

"As we age, immigration both from other states and from abroad [takes] on a new importance," Brower said. "Particularly when it's in the context of the current employment situation that we have, it's concerning to see this trend move in this direction from an employment perspective."

India, Mexico top list

Census data shows that the leading birthplace of people who moved to Minnesota from abroad in recent years was India, followed by Mexico, China and Somalia. Some come here for specialized jobs on H1-B visas, which the federal government denied at a higher rate last year.

Sandra Feist, an employment-based immigration attorney, said visa applications have become much more unpredictable and stressful for employers and employees. Immigration officials now routinely request additional information that should be self-evident, Feist said, like whether highly skilled jobs require a bachelor's degree. That slows down the process, she said.

The trend of international students in Minnesota was less clear. The number of foreign students enrolled in Minnesota colleges and universities rose by 2% last year, according to the Institute of International Education, a New York-based nonprofit organization.

But the number of international freshmen at the University of Minnesota dropped 27% this academic year compared to the year prior. The number of international undergraduates declined by 6%, though international graduate students rose slightly.

Jennifer Schulz, communications director for the university's Global Programs and Strategy Alliance, said there have not been major visa problems.

Schulz said competition from other countries, the cost of tuition, the U.S. political climate around immigration and gun violence contributed to the decline. More international students are also applying to multiple schools, meaning applications were steady but fewer students were enrolled.

Staff writer Danish Raza contributed to this report.