The Trump administration plans to ramp up efforts to strip some naturalized Americans of their citizenship, according to internal guidance obtained by The New York Times, marking an aggressive new phase in President Trump’s immigration crackdown. The guidance, issued on Tuesday to U.S. Citizenship and Immigration Services field offices, asks that they “supply Office of Immigration Litigation with 100-200 denaturalization cases per month” in the 2026 fiscal year. If the cases are successful, it would represent a massive escalation of denaturalization in the modern era, experts said. By comparison, between 2017 and this year to date, there had been just over 120 cases filed, according to the Justice Department. Under federal law, people may be denaturalized only if they committed fraud while applying for citizenship, or in a few other narrow circumstances. But the Trump administration has shown a zeal for using every tool at its disposal to target legal and illegal immigrants, leading activists to warn that such a campaign could sweep up people who had made honest mistakes on their citizenship paperwork and sow fear among law-abiding Americans. The guidance comes as Mr. Trump has spent much of this year closing loopholes in the immigration system and throwing up roadblocks for people seeking to enter and stay in the country. The sweeping campaign, which has gone further than purging the country of unlawful migrants, has included blocks on asylum at the southern border, a pause on asylum applications inside the United States, and a ban on entry for travelers from predominantly African and Middle Eastern nations. Officials say their actions will make the country safer and preserve the country’s values. A targeted campaign to increase the number of American immigrants stripped of their citizenship represents an escalation of an already ambitious campaign. “It’s no secret that U.S. Citizenship and Immigration Services’ war on fraud includes prioritizing those who’ve unlawfully obtained U.S. citizenship — especially under the previous administration,” said Matthew J. Tragesser, a U.S.C.I.S. spokesman. “We will pursue denaturalization proceedings for those individuals lying or misrepresenting themselves during the naturalization process. We look forward to continuing to work with the Department of Justice to restore integrity to America’s immigration system.” In interviews, some former agency officials expressed concern at the scale of the case goals for denaturalization pushed by U.S.C.I.S. leadership. “Imposing arbitrary numerical targets on denaturalization cases risks politicizing citizenship revocation,” said Sarah Pierce, a former U.S.C.I.S. official. “And requiring monthly quotas that are 10 times higher than the total annual number of denaturalizations in recent years turns a serious and rare tool into a blunt instrument and fuels unnecessary fear and uncertainty for the millions of naturalized Americans.” Proponents of stricter immigration laws said it was necessary to more aggressively root out people who had been improperly granted citizenship. “I don’t think we’re anywhere close to denaturalizing too many people,” said Mark Krikorian, the head of the Center for Immigration Studies, a group that favors restrictive immigration policies. Mr. Krikorian said that the country was “so far from denaturalizing” enough people that such an effort would not pull in people who should not be targeted. There are about 26 million naturalized Americans in the country, according to the Census Bureau. More than 800,000 new citizens were sworn in last year, most of whom were born in Mexico, India, the Philippines, the Dominican Republic or Vietnam, U.S.C.I.S. statistics show. Most people stripped of their citizenship revert to being legal permanent residents. The new guidance on Tuesday was part of a document laying out U.S.C.I.S. priorities for the 2026 fiscal year, which began in October. Listed alongside such goals as “provide employee feedback opportunities” and “strengthen management of high-risk cases” was “pursue denaturalization.” The Justice Department previously also said it would make denaturalization a priority this year. In a memo distributed in the summer, officials laid out their approach, saying they would target individuals in an array of categories beyond committing fraud in obtaining citizenship. Categories of eligible people include gang members, those who committed financial fraud, individuals connected to drug cartels and violent criminals, according to the department. “The civil division shall prioritize and maximally pursue denaturalization proceedings in all cases permitted by law and supported by the evidence,” the agency wrote in June.ImageUnder federal law, people may be denaturalized only if they committed fraud while applying for citizenship, or in a few other narrow circumstances. Credit...Charles Krupa/Associated Press U.S.C.I.S. is a key player in the process of denaturalization. The agency refers cases to the Justice Department, which must go through a federal court to strip someone of their citizenship. The process can occur either through a civil or a criminal proceeding. During a civil case, government lawyers must have “unequivocal evidence” that someone obtained citizenship illegally or hid a material fact during the process. Because the government must go through a challenging court process, denaturalization cases have been rare since the 1990s. A Bloomberg Law analysis found that denaturalization cases brought by the government since then peaked in 2018, when 90 criminal and civil cases were filed. “The Supreme Court has repeatedly stated that citizenship and naturalization are too precious and fundamental to our democracy for the government to take it away on their whim. Instead of wasting resources digging through Americans’ files, U.S.C.I.S. should do its job of processing applications, as Congress mandated,” said Amanda Baran, a former senior U.S.C.I.S. official in the Biden administration. Mr. Trump stepped up denaturalizations in his first term as well. In one widely publicized case, a New Jersey man born in India, Baljinder Singh, was stripped of his citizenship after the Justice Department found that he had arrived in the country without travel documents or proof of identity and that he had used a different name. This year, the Justice Department has brought 13 denaturalization cases and won eight of them, according to Chad Gilmartin, an agency spokesman. Mr. Gilmartin said in a social media post earlier this year that there had been over 100 cases filed to the courts during the first Trump administration, compared with 24 during the Biden administration. In 2017, the Supreme Court ruled that the government must prove not only that someone had lied during the citizenship application process but that the lie had an impact on the underlying citizenship claim. Experts said that despite the ramp-up in referrals, the process to actually denaturalize someone would likely remain quite difficult, raising questions on whether the government will actually be able to get many cases through. Still, some had concerns about what the guidance could portend. “My fear would be that as we have seen in the arrest and removal context when D.H.S. employees are given arbitrary targets what happens is people who shouldn’t be swept up, get swept up and that you’re going to see that happening to people in this context as well,” said Margy O’Herron, a senior fellow at the Brennan Center, a nonpartisan law and policy organization. “That could incite fear and terror amongst naturalized citizens.”