A 21-year-old US man on deployment in Darwin has tested positive for coronavirus.
The man has been in quarantine since his arrival in Darwin on Wednesday.
About 1200 Marines are coming to Darwin as part of the ninth Marine Rotational Force - Darwin (MRF-D).
Complying with the current guidelines, the man has been in quarantine on barracks in Darwin since arrival.
He has had no contact with the public.
The man is now under the care of Royal Darwin Hospital in isolation.
The Marine was part of a third group of Marines who arrived on Wednesday.
The Marine is the second active case of coronavirus in the NT after a Darwin man was confirmed to have contracted coronavirus after flying into the Territory earlier in the month.
The Darwin man was the first new confirmed case of coronavirus since early April.
The NT will open its borders next Friday, July 17 to all but Victoria.
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