Last week a 30-year-old female passenger on the same United Airlines flight was reported to have Covid-19.
Follow-up contact tracing then tested a 53-year-old male and he was confirmed positive.
The new case is asymptomatic and a returning resident.
The government has assured people that even with the additional cases, the community's vulnerability level remains unchanged because of a higher number of negative results among an increasing number of residents being tested.
As 7 June, more than 7,200 people had been tested for Covid-19 in the CNMI.