The Trump administration's new 45,000 cap on refugees will include people resettled in the US under a deal struck with Australia.
This week more than 50 refugees who had been in limbo for years on Manus Island and Nauru departed for a new life in the US.
Up to 1,250 refugees are expected to be resettled in the US.
The US resettlement agreement was the subject of a heated phone call between Donald Trump and Prime Minister Malcolm Turnbull in January in which the new US president characterised the deal as dumb.
Mr Trump has since reluctantly agreed to honour the agreement, which Mr Turnbull struck with the Obama administration.
Overnight, the White House released a document outlining the new cap for the 2018 financial year, which is the lowest in decades.
The Trump administration says the lower cap is necessary so that US officials can address a growing backlog of people applying for asylum inside the United States and to do better vetting of refugees.
Refugee advocates say the lower limit ignores growing humanitarian crises around the world that are causing people to flee their native countries in greater numbers and represents a departure from US global leadership.
Former President Barack Obama had wanted the US to accept 110,000 refugees in 2017, but the end of the financial year total will actually fall short at 45,000.
Asked if the US refugee resettlement deal was affected by the new cap, a spokesman for Australia's immigration department said: "Questions about the US refugee program should be directed to the US."
The US State Department has told reporters in a special briefing that the new cap will include the intake from Nauru and Manus Island.
