The United States is on pace to accept one of the lowest numbers of refugees on record under sweeping restrictions imposed by the Trump administration.

State Department figures show that 12,151 refugees arrived in the United States as of March 31, six months into the fiscal year that began Oct. 1. If the number of admissions continues at the same pace in the second half of the year, the total will fall 19 percent below the historically low ceiling of 30,000 set by President Trump.

The United States is now in the third year of an overall slowdown in refu­gee numbers, despite a continuing crisis. Worldwide, 68 million people have been forcibly displaced, and more than 25 million are refugees. Groups that work with refugees say it is not that fewer people are seeking to come to the United States but that far fewer are able to gain admission.

The United States traditionally has been willing to accept the world’s most vulnerable refugees. Many of them are religious minorities in their home countries and are fleeing persecution.

The latest refu­gee statistics show the dramatic impact of the Trump administration’s overhaul of the U.S. immigration system, beginning with an executive order in the president’s first week in office. He suspended refu­gee admissions, blocked refugees from some predominantly Muslim countries and lowered the admissions ceiling by more than half. Refugee numbers have plummeted so much that some resettlement centers have closed offices around the country.

Last year’s admissions were the lowest since Congress created the refu­gee program in 1980 for people fleeing persecution — just half the maximum of 45,000 were actually accepted to resettle in the United States.

The cap was dropped again this year, to an all-time low, but it is too early to say whether the 22,500 admissions of last year will be surpassed.

A State Department spokesman said that the admission ceiling of 30,000 refugees is an upper limit, not a target, and that the pace of admissions could quicken.

“Refugee admissions rarely proceed at a steady pace throughout the year and are often higher in the second half of the year,” the spokesman said, speaking on the condition of anonymity under State Department rules. “It is premature to predict the number of refugees who will ultimately be admitted” by the end of the fiscal year.

Compared with 2016, the number of refugees coming to the United States is down 71 percent.

The change is as much about who is coming as about how many.

According to calculations by World Relief, a charity that helps refugees adjust to life in the United States, the number of Muslims accepted is down 90 percent in the past three years. But the statistics also show a 47 percent drop in Christian refugees, and a 72 percent decrease in Christians from the 50 countries on the World Watch list that Open Doors USA maintains of nations in which Christians face the most persecution.

World Relief President Scott Arbeiter said Americans are capable of and willing to accept many more refugees.

“We are gravely concerned that the U.S. has abdicated its role in exemplifying the moral leadership needed to meet the needs of the most vulnerable displaced around the world,” he said in a statement. “Furthermore, the dramatic decrease in the numbers of persecuted Christian and other religious minority refugees resettled in the U.S. to escape religious persecution contradicts the administration’s previously stated willingness to help these populations.”

The Trump administration has expressed concern for Christian and Yazidi minorities in Iraq. Under pressure from Vice President Pence, the U.S. Agency for International Development has earmarked funds specifically for those groups, which suffered under the Islamic State.

During 2016, the United States admitted 1,524 Iraqi Christians and 417 Yazidis from Iraq and Syria. Last year, the number shrank to 26 Iraqi Christians and five Yazidis. In the past six months, 41 Iraqi Christians and nine Yazidis were admitted.

One reason the numbers were lower in fiscal 2018 than this year is that admissions were restricted for several months while the administration reviewed its vetting procedures.

Because the United States has traditionally said it is willing to accept the most vulnerable refugees, many of those who have come are fleeing religious persecution.

“The United States remains committed to advancing international religious freedom, including the protection of religious groups, across the globe,” the State Department spokesman said. “The United States will continue to resettle the most vulnerable refugees, including those who have fled religious persecution, while prioritizing the safety and security of the American people.”

Secretary of State Mike Pompeo has said religious freedom is a priority of the administration. He hosted a high-level global meeting on the issue at the State Department last year and plans a second this summer.

Pompeo met with four Uighur Muslims last week and has increasingly spoken out about human rights abuses in China against Uighurs and other religious minorities.

Now there are deep cuts in the numbers of refugees coming from almost every country and every religious category.

Only one Iranian Jew was admitted as a refu­gee last year, compared with 72 in 2016. So far this year there have been none.

Christians and Muslims from Myanmar, primarily Rohingya, are about a third of what they were in 2016. Christians from Pakistan have dropped by half.

The share of those who come also has shifted. Muslim refugees outnumbered Christian refugees in 2016. Now 81 percent are Christian, and 15 percent are Muslim.

There are far fewer spots, though. The number of Christian refugees from the World Watch list has dropped from 16,700 in 2016 to 4,440 last year, and is running at a similar level this year.

“If the administration wants to help religious minorities, then you have to fix the whole program,” said Jenny Yang, advocacy director for World Relief. “You have to select the most vulnerable refugees to come in. But they can’t come in through channels that are increasingly restricted.”