For the first time in years, the number of H-1B visa applications has decreased — a signal that President Trump’s “America First” rhetoric is deterring employers from hiring foreign workers, experts say.

That rhetoric will ramp up Tuesday, when Trump is planning to sign an executive order that seeks to make changes to the visa program.

The United States Citizenship and Immigration Services said Monday it had received 199,000 H-1B applications for the next fiscal year, according to the federal immigration agency. This is a steep decline from the 236,000 received last year and the 233,000 it received in 2015.

Trump is heading to Kenosha, Wisconsin, where he plans to sign an order dubbed “Buy American, Hire American,” administration officials said.

The officials, who spoke on condition of anonymity despite the president’s criticism of unnamed sources, said the order, which Trump will sign at the headquarters of tool manufacturer Snap-on Inc., would direct the departments of Homeland Security, Justice, Labor and State to propose new rules to prevent immigration fraud and abuse. Those departments would also be asked to offer changes so that H-1B visas are awarded to the “most-skilled or highest-paid applicants.”

The H-1B visa allows foreign workers with specialized skills to spend up to six years working at a sponsor company in the United States. Silicon Valley tech companies — from young startups to companies as established as Google — have come to rely on these coveted work visas to fill engineering positions. But while demand has increased, the number of visas granted to for-profit companies has remained the same, at 85,000, since 2005.

Given the uncertainty over the fate of the program under Trump and the strong economy, immigration attorneys expected a surge in applications this year. But, instead, this year’s numbers are “surprisingly low,” said William Stock, president of the American Immigration Lawyers Association.

“A lot of people are looking at America, and (wondering) if it is still a place to make business,” Stock said.

During his campaign, Trump said at some points he supported high-skilled visas, then came out against them. At one debate, he called for fully ending the program, saying: “It’s very bad for our workers and it’s unfair for our workers. And we should end it.”

The officials said the changes could be administrative or legislative and could include higher fees for the visas, changing the wage scale for the program or other initiatives.

The H-1B visa program has been a constant point of contention between Silicon Valley and Washington. While tech companies have long argued that there are not enough visas available to fulfill the demand, critics — including the Trump administration — say that the visas are used by companies to squeeze out American workers in favor of foreigners who will work for less.

Congress is considering several bills to overhaul the visa program. One, introduced by Illinois Democratic Sen. Dick Durbin and Iowa Republican Sen. Chuck Grassley, would require companies seeking H-1B visas to first make a good-faith effort to hire Americans, a requirement many companies can dodge under the current system; give the Labor Department more power to investigate and sanction H-1B abuses; and give “the best and brightest” foreign students studying in the U.S. priority in getting H-1B visas.

The immigration agency said this month that it will take a “more targeted approach” in choosing employers whose workers receive visas — a move some experts say will challenge tech-outsourcing companies that consistently file large numbers of applications every year.

A reason behind the drop, Stock said, could be that companies that hire engineers to handle other businesses’ programming needs may have filed fewer applications. India’s Infosys, Tata Consultancy Services and Wipro accounted for the majority of H-1B applications filed in California last year.

In a call with Wall Street analysts to discuss its fourth-quarter earnings Monday, Infosys CEO Vishal Sikka said the company will expand its local hiring to “mitigate any potential risks from visa regulations in the U.S.”

Infosys could not be reached for comment.

A recent Chronicle analysis found that such tech-outsourcing companies pay certain employees holding H-1B visas close to a prevailing wage calculated by the Department of Labor. In the job categories studied, large American tech companies — Google, Facebook and Apple — paid H-1B employees significantly more.

Another reason behind the drop in applications could be frustrations around the H-1B lottery process, where applicants are randomly selected and often have to wait several months for a decision, said Martin Lawler, a Bay Area immigration attorney.

Lawler said H-1B visas are critical for Silicon Valley.

“We need more math-based professionals, and it is quite depressing that we can’t go out and get the best and brightest,” he said, adding that demand “is going to continue so long as Silicon Valley is doing well.”

Since Trump has taken office, federal officials have shifted some ground rules on the coveted work visa program.

According to guidance issued on the same day that the petition period opened, computer programmers with bachelor’s degrees are no longer automatically eligible for an H-1B visa. The reversal of a 17-year- old federal policy meant companies must provide more documentation of the need for an advanced degree to do a job.

In March, the federal immigration agency temporarily suspended a program which allowed companies to pay a fee to have a petition reviewed within 15 days, saying it had a backlog of applications. The premium processing program will remain suspended for up to six months. Some companies relied on the faster review so they could make a quick decision on hiring an employee who needed a visa.

It is unclear how the suspension of premium processing and the new guidance for programmers affected the number of applications received this year.

Ira Mehlman, spokesman for Federation for American Immigration Reform, said this drop is not surprising, given the administration’s promise to keep a closer eye of potential abuses of the system.

“This is a good thing for the sake of a lot of people that have trained in these (science, engineering, technology and math) fields — but are finding themselves working in other sectors of the economy,” he said.

Mehlman said he hopes the number of applications continues to drop.

The Associated Press contributed to this report.

Trisha Thadani is a San Francisco Chronicle staff writer. Email: tthadani@sfchronicle.com Twitter: @TrishaThadani