DARWIN, Australia – The first group of 200 U.S. Marines have arrived in tropical northern Australia for their annual rotation despite the coronavirus pandemic border closures.

Defense Minister Linda Reynolds said on Tuesday the marines were tested for COVID-19 on arrival in Darwin and will be quarantined in military facilities for the next 14 days.

The ninth annual rotation was delayed this year by two months due to the pandemic. Only 1,200 marines will come to Australia this year during the current dry season, fewer than half the 2,500 that participated last year.

The remaining marines will arrive through July and leave in September before the monsoonal rains come.

The Northern Territory was declared coronavirus free almost two weeks ago, but its borders remain closed to non-essential travel.

All 30 COVID-19 cases detected in the Northern Territory were connected to interstate and overseas travel. All have since recovered.