Howard Springs expects to cater for up to 2000 arrivals between May and June, with a peak of 1200 in May, under the territory's agreement with the federal government.

The new staff this week completed their training ahead of joining the expanded quarantine operation based near Darwin Airport.

Another 150 workers will be inducted in May, NT Health Minister Natasha Fyles said in a statement on Friday.

"We are working with AUSMAT to ensure Howard Springs remains the gold standard when it comes to repatriating returned Australians," she said.

A total of 400 staff are being recruited to expand capacity at Howard Springs from 850 to 2000 returning travellers per fortnight.

NT Chief Minister Michael Gunner this week said his government was ready to welcome more travellers from India, which is in the midst of a severe outbreak of the deadly disease.

"We have the capacity to look after returning Australians and keep coronavirus where it should be, trapped in that quarantine centre," he said.

The federal government this week suspended flights into Australia from India due to the outbreak, which is running at about 300,000 new cases a day, until May 15.

Many of the people returning to Australia before the ban were travelling from India and a number have tested positive for COVID-19 upon their return in the NT, Western Australia and other states.

Prime Minister Scott Morrison on Wednesday toured Howard Springs to discuss the expansion of the facility.

The centre hasn't had a COVID-19 case breach since it began regularly taking in repatriated Australians in October.

So far it's catered to more than 6500 returnees.

Meanwhile, another US Marine has tested positive for COVID-19 after arriving in the Top End as part of the Darwin-based Marine Rotational Force.

The 20-year-old is asymptomatic and is being cared for by the AUSMAT team at Howard Springs, the government said on Friday.

Australian Associated Press