Washington, Dec 23 : US immigration authorities say they are tightening oversight of H-1B visas and other legal immigration programs, citing fraud investigations, new regulatory limits, and a broader enforcement push outlined in a year-end review released.

The US Citizenship and Immigration Services said it has stepped up scrutiny of employment-based, student, and family-based immigration, including through its largest enforcement effort to date, Operation Twin Shield.

The operation uncovered what the agency described as widespread abuse of H-1B and student visas and fraudulent marriage-based applications, leading to thousands of worksite visits, nearly 1,500 in-person interviews, benefit denials, and arrests by USCIS.

USCIS said it has also changed the rules governing employment authorization, ending automatic extensions for certain work permits while renewal applications are pending.

The agency reduced the maximum validity of some employment authorization documents from five years to 18 months, saying the move allows more frequent screening and vetting of applicants.

USCIS highlighted a proposed rule to prioritize H-1B visas for higher-skilled, higher-paid workers. The agency said the change is intended to protect wages, working conditions, and job opportunities for American workers. USCIS also issued a separate rule to streamline agricultural work visas to support what it called the countryâ??s â??vital agricultural industry.

Family-based immigration has also come under closer examination. USCIS said it has enhanced screening to ensure marriages and family relationships cited in immigration applications are genuine and not fraudulent schemes to obtain benefits.

The measures are part of a broader shift under Homeland Security Secretary Kristi Noem and USCIS Director Joseph B. Edlow toward what the agency described as an â??America Firstâ?? immigration policy focused on public safety and national security.

â??With Secretary Noem in charge of homeland security, USCIS has taken an â??America Firstâ?? approach, restoring order, security, integrity, and accountability to Americaâ??s immigration system,â?? Edlow said in the review.

According to the report, USCIS referred more than 14,400 people to ICE since Jan. 20 for public safety, national security, and fraud concerns. Among them were 182 individuals identified as confirmed or suspected national security risks. The agency said cooperation with other law enforcement bodies resulted in more than 2,400 arrests at USCIS field offices during the year.

Following a Nov. 26 attack involving an Afghan national, USCIS said it temporarily halted asylum processing for certain groups, ordered a re-examination of green card applications from designated high-risk countries, and paused processing of some immigration petitions from Afghanistan and other countries of concern. Officers were directed to weigh country-specific risk factors when vetting applicants from 19 high-risk nations.

The agency also announced the launch of a new vetting center on Dec. 5, aimed at strengthening the screening of immigration applications through advanced technologies and closer coordination with law enforcement and intelligence agencies.

USCIS said it has â??declared war on immigration fraud,â?? reporting more than 29,000 fraud referrals since January 20.

/IANS