WASHINGTON — The White House is considering a second sharp reduction in the number of refugees who can be resettled in the United States, picking up where President Trump left off in 2017 in scaling back a program intended to offer protection to the world’s most vulnerable people, according to two former government officials and another person familiar with the talks.

This time, the effort is meeting with less resistance from inside the Trump administration because of the success that Stephen Miller, the president’s senior policy adviser and an architect of his anti-immigration agenda, has had in installing allies in key positions who are ready to sign off on deep cuts.

Last year, after a fierce internal battle that pitted Mr. Miller, who advocated a limit as low as 15,000, against officials at the Department of Homeland Security, the State Department and the Pentagon, Mr. Trump set the cap at 45,000, a historic low. Under one plan currently being discussed, no more than 25,000 refugees could be resettled in the United States next year, a cut of more than 40 percent from this year’s limit. It would be the lowest number of refugees admitted to the country since the creation of the program in 1980.

The program’s fate could hinge on Mike Pompeo, the secretary of state. His department has traditionally been a strong advocate for the refugee program, but Mr. Pompeo is now being advised by two senior aides who are close to Mr. Miller and share his hard-line approach, according to the people briefed on the discussions, who spoke on the condition of anonymity because they were not authorized to reveal internal deliberation about a decision that has yet to be completed.