Minnesota’s labor force is growing more slowly this decade than it did in the past three, a trend that will continue into the 2020s and likely lead to a push for more immigration, a group of business leaders and economists said Friday.

In the nearly finished presidential campaign, much of the immigration debate has centered on how accommodating the United States should be on immigration. But in a workshop sponsored by Global Minnesota, the foreign affairs interest group at the ­University of Minnesota, participants said Minnesota’s future growth is likely to depend on an expanded flow of immigrants.

And while the influx of immigrants since 2000 has created the impression that the state is seeing more new faces than ever, immigration in Minnesota is still below the levels of a century ago.

In 1920, 483,000 people in Minnesota, or about 20 percent of the population, were born in another country. That contrasts with 474,000 people, or about 9 percent of the population, today who were born in another country, state demographer Susan Brower said at the workshop.

These immigrants are responsible for much of the growth in the state’s labor force, helping Minnesota compensate for the huge number of baby boomers who are retiring each year.

But that growth rate has slowed markedly in recent years. This decade, Minnesota’s labor force is expected to grow by about 8,000 workers a year on average, down from a pace of 38,000 a year in the 1990s. It’s expected to slow even further in the 2020s, to around 4,000 workers a year.

“When we make these projections, we’ve done it with the assumption that immigration is going to increase a little bit,” Brower said. “It becomes a very central part of how we grow when we look at immigration in the context of these very slow growth numbers.”

The Minnesota Chamber of Commerce recently studied the effect of immigrants on the state’s business scene and found that 40 percent of the state’s largest businesses were started by them, said Bill Blazar, a chamber senior vice president.

“What we discovered is that it’s certainly true that immigrants are key to the development of the state’s economy as workers. But we also found that they play a really key role as entrepreneurs,” Blazar said. “We really depend on the start-up and success of new companies, so having a population of folks who are oriented toward entrepreneurship is a key contribution to the economy.”

Sadiq Abdirahman, a manager at the Minnesota Department of Administration who as a child was one of the first Somali immigrants in the state, recalled being offered a job at a turkey plant in Marshall the first day he arrived. When immigrants arrive, he said, they often need assistance before becoming full contributors to the economy.

“What is our gift?” he asked. “Our gift is our children, who are Minnesotans.”

In one example of the generational advance most immigrants make, Milissa Silva-Diaz, chief executive of El Burrito Mercado, spoke about being the granddaughter of Mexican immigrants who worked in Minnesota sugar beet fields and the child of an entrepreneurial couple who started the St. Paul restaurant and market. Silva-Diaz, her sister and niece recently took over ownership of El Burrito Mercado, overseeing 85 people.

“We now have second-generation owners and we’re all women — and all three of us work our butts off,” she said.