The Minnesota Department of Health announced on Thursday that a Minnesota resident has tested positive for the new omicron variant of the coronavirus, and said that person recently traveled to New York City. 

The person, an adult male, developed mild symptoms Nov. 22 and sought a COVID-19 test Nov. 24, health officials said. His symptoms have since resolved.

The Minnesota Department of Health said the person attended the Anime NYC 2021 convention at the Javits Center from Nov. 19-21, and was fully vaccinated.

In a Thursday morning news conference, New York Gov. Kathy Hochul said the state has been in touch with the Javits Center and New York City.

She encouraged anyone who attended a conference at the Javits Center between Nov. 18 and Nov. 22 to get tested for COVID-19, and said the state had a way to reach out to those individuals.

In a statement, New York City Mayor Bill de Blasio said New Yorkers "should assume there is community spread of the variant in our city."

De Blasio said the city was working with the state, the CDC and the Javits Center. He reiterated that anyone who attended the conference should get tested, and said the city's Test and Trace Corps would also be reaching out to attendees.

Hochul and de Blasio both said that attendees of the conference were required to be vaccinated. According to the conference's website, attendees were allowed to attend "immediately after their first dose," as per the city's "Key to NYC" initiative.

De Blasio added that the conference required masks.

Hochul said the situation was "not cause for alarm."

"Again, it was foreseen ever since it was first reported out of South Africa, that we knew it would come to New York state at some point," Hochul said. "And I want all New Yorkers to know that their state government, in collaboration with our local governments, our cities and our counties, are prepared for this."

Hochul added that there were currently no known cases of the omicron variant in New York at this time.

"There is one way to address this: New Yorkers, get vaccinated, get boosted and get ready," she said.

In a statement, CDC Director Dr. Rochelle Walensky said the CDC is working closely with Minnesota's Department of Health, and that it has been actively monitoring and preparing for the variant.

"CDC has expanded its capacity for genomic sequencing over the past nine months and we have more tools to fight the variant than we had at this time last year from vaccines to boosters to the prevention strategies that we know work including masking in indoor public settings, washing your hands frequently and physical distancing. These methods work to prevent the spread of COVID-19, no matter the genetic sequence," Walensky's statement reads, in part.

The Minnesota case comes a day after health officials in California announced Wednesday they discovered the first known omicron infection in the U.S. That individual had recently traveled to South Africa, where the variant was first identified.

Much is unknown about the omicron variant, which the World Health Organization says has more than 30 mutations on the spike protein that binds to human cells. Several countries, including the United States, have restricted travel from South Africa and neighboring countries as a precaution.

Health officials say it will take another two to four weeks before enough real-world data are available to determine just how transmissible omicron is, whether it is more likely to result in serious illness or what impact it has on the effectiveness of existing vaccines.