WASHINGTON (Reuters) - The U.S. Labor Department said on Tuesday it is stepping up efforts to root out potential fraud in its visa programs for foreign workers, a move that will include increases in both civil investigations as well as criminal referrals.

The announcement by Labor Secretary Alexander Acosta follows President Donald Trump in April ordering a review of the U.S. visa program as part of his “America First” campaign pledge.

The April executive order specifically entailed a review of the H-1B visa program, which is routinely used by technology firms like Tata Consultancy Services Ltd, Cognizant Technology Solutions Corp and Infosys Ltd to bring skilled foreign workers, such as engineers, to jobs in the United States.

Critics of the program, including Trump senior adviser Stephen Miller, have argued the laws governing these visas are lax and make it too easy for companies to replace U.S. workers with less-expensive foreign labor.

The U.S. Labor Department and Department of Homeland Security each play a role in reviewing the applications for foreign guest workers.

In April, Homeland Security said it was planning to take steps as well to prevent fraud in the H-1B visa program.

Labor Department officials said Tuesday the increased enforcement efforts will involve all of the foreign visa worker programs, including H-2A and H-2B visas.

Those steps include directing the department’s wage and hour division to “use all its tools” to conduct civil probes, ramping up criminal referrals to the department’s inspector general and instructing the employment and training office to propose changes to the H-1B labor condition application that companies file when they seek to hire foreign skilled guest workers.

“Entities who engage in visa program fraud and abuse are breaking our laws and are harming American workers,” Acosta said in a statement.

A senior Labor Department official acknowledged there are legal limitations in the department’s authority over H-1B visas. Exemptions in the law, for instance, allow companies to skirt requirements to protect American workers, and the department’s authority to investigate is restricted.

The official said the department was looking into whether to ask Congress to amend the law.

A bill introduced earlier this year by Republican Senator Charles Grassley of Iowa and Democratic Senator Dick Durbin of Illinois would give the department more powers to go after H-1B violators.