About three-fourths of those convicted on terrorism charges since 9/11 are foreign-born—and more than half of those aren’t U.S. citizens, according to a new report from the Justice Department and the Department of Homeland Security.

Still, the joint report issued Tuesday finds that prosecutors lodged more than half of all terrorism charges—295 out of 549—against U.S. citizens either by birth or naturalization.

A merit-based immigration system that favors immigrants who are able to fill needed jobs is more likely to attract immigrants who will be successful than does the current family-based system allowing chain migration, a senior Trump administration official told reporters in a conference call.

President Donald Trump favors the merit policy along with stronger border security and an end to the visa lottery system.

More successful immigrants would contribute to the prosperity and security of the country, the senior administration official said.

Though a merit-based system would be economically beneficial, it largely would be disconnected from security, said David Inserra, a policy analyst in homeland security at The Heritage Foundation.

“It depends on how we look at why someone becomes a terrorist. If we think it’s just poor people, then an economic system would change that, but we know that’s not the case,” Inserra, who maintains a database of terror plots against U.S. targets for The Heritage Foundation, told The Daily Signal.

Noting the number of naturalized citizens who become radicalized on the list in the Justice and Homeland Security report, Inserra said the bigger problem is with assimilation.

“If someone comes to the United States and becomes a terrorist 20 years later, that’s not a vetting problem, that’s an assimilation problem,” Inserra said.

Trump signed an executive order in March that required the report, which is focused on vetting immigrants and protecting Americans.

Other key highlights include:

—At least 549 individuals were convicted of international terrorism-related charges in federal courts between Sept. 11, 2001, and Dec. 31, 2016. Of them, 402 were foreign-born.

—A total of 254 of the 549 convicted were not U.S. citizens; 148 were foreign-born, naturalized, and were granted U.S. citizenship. Another 147 were U.S. citizens by birth.

—Immigration and Customs Enforcement removed 1,716 immigrants based on national security concerns.

—The Department of Homeland Security encountered 2,554 individuals on the terrorist watch list traveling inside the United States during fiscal year 2017, which began Oct. 1, 2016. Of them, 335 tried to enter the country by land, 2,170 sought to enter by air, and 49 tried to enter by sea.

—Authorities arrested 355,345 noncitizen offenders from Oct. 1, 2011, to Sept. 30, 2017, after they were convicted of an aggravated felony. During that same time, 372,098 non-U.S. citizen offenders were removed from the United States after conviction of an aggravated felony or two or more felonies.

—Citizenship and Immigration Services referred 45,858 foreign nationals who applied for immigration benefits to ICE on suspicion of fraud between 2007 and 2017. Officials indicated that the foreign nationals had committed egregious, public safety-related offenses within the U.S.

—From 2010 through 2016, Customs and Border Protection identified and prevented the boarding of 73,261 foreign travelers on flights destined for the U.S. because they posed a risk.

In a written statement, Homeland Security Secretary Kirstjen Nielsen said:

This report is a clear reminder of why we cannot continue to rely on immigration policy based on pre-9/11 thinking that leaves us woefully vulnerable to foreign-born terrorists, and why we must examine our visa laws and continue to intensify screening and vetting of individuals traveling to the United States to prevent terrorists, criminals, and other dangerous individuals from reaching our country.

Without legislative change, DHS will continue to see thousands of terrorists a year attempt to enter the United States, and while we must be right every time, the terrorists only need to be lucky once.

Attorney General Jeff Sessions called the findings in the report “sobering.”

“And the information in this report is only the tip of the iceberg: We currently have terrorism-related investigations against thousands of people in the United States, including hundreds of people who came here as refugees,” Sessions said in a prepared statement, adding:

Our law enforcement professionals do amazing work, but it is simply not reasonable to keep asking them to risk their lives to enforce the law while we admit thousands every year without sufficient knowledge about their backgrounds. The pillars of President Trump’s immigration policy—securing our porous borders, moving to a merit-based immigration system that ends the use of diversity visas and chain migration, and enforcing our nation’s laws—will make their jobs easier and make the United States a safer place.