Researchers at Icahn School of Medicine at Mount Sinai say the large-scale Chinese coronavirus outbreak in New York City, New York, “predominately” came from Europe.

In a study published Thursday, Mount Sinai researchers traced the source of coronavirus cases in New York City, which “predominately arose through untracked transmission between the United States and Europe,” they say.

“We sequenced genomes from COVID-19 cases identified up to March 18,” Harm van Bakel, PhD, said in a news release. “These cases were drawn from 21 New York City neighborhoods across four boroughs (Manhattan, Bronx, Queens and Brooklyn), as well as two towns in neighboring Westchester County.”

The researchers concluded that multiple independent cases of coronavirus arrived in New York City primarily from Europe and other regions of the U.S. like Seattle, Washington. The study reveals that the coronavirus may have been circulating in New York City in late January, weeks before President Donald Trump ordered a ban on travel from Europe.

“These results show that [coronavirus] came to the New York City area predominately via Europe through untracked transmissions,” Viviana Simon, MD, PhD, said.

“Only one of the cases studied was infected with a virus that was a clear candidate for introduction from Asia, and that virus is most closely related to viral isolates from Seattle, Washington,” Simon said. “The study also suggests that the virus was likely circulating as early as late-January 2020 in the New York City area. This underscores the urgent need for early and continued broad testing to identify untracked transmission clusters in the community.”

Since March 13, a travel ban on Europe has prevented recent European travelers and Europeans from entering the U.S. through international flights. Trump’s travel bans on China, Iran, and Europe have been hugely supported by American citizens — 95 percent of whom say the restrictions are necessary to stop the spread of the coronavirus.

Travel from other highly-affected coronavirus regions, though, have continued to the U.S. For example, daily flights from Brazil — where there are more than 18,000 confirmed coronavirus cases — are landing in major cities like Miami, Florida, and Dallas, Texas.

While the State Department has stopped visa processing for most of all visas, H-2A and H-2B foreign workers are being fast-tracked to the U.S. to take American agricultural and nonagricultural jobs with minimal screenings. These foreign workers primarily arrive from Mexico, where there are nearly 3,200 confirmed coronavirus cases and Central America where hundreds have contracted the virus.

John Binder is a reporter for Breitbart News. Follow him on Twitter at @JxhnBinder.