LAS VEGAS >> Agustina Ocampo is the kind of foreign traveler businesses salivate over.

The 22-year-old Argentine recently dropped more than $5,000 on food, hotels and clothes in Las Vegas during a trip that also took her to Seattle’s Space Needle, Disneyland and the San Diego Zoo. But she doubts she will return soon.

"It is a little bit of a headache," said Ocampo, a student who waited months to find out whether her tourist visa application would be approved.

More than a decade after the federal government strengthened travel requirements after the Sept. 11, 2001, terrorist attacks, foreign visitors say getting a temporary visa remains a daunting and sometimes insurmountable hurdle.

The tourism industry hopes to change that with a campaign to persuade Congress to overhaul the State Department’s tourist visa application process.

"After 9/11, we were all shaken and there was a real concern for security, and I still think that concern exists," said Jim Evans, a former hotel chain CEO heading a national effort to promote foreign travel to the U.S.

At the same time, he said, the U.S. needs "to be more cognizant of the importance of every single traveler."

Tourism leaders said the decline in foreign visitors over the past decade is costing American businesses and workers $859 billion in untapped revenue and at least half a million potential jobs at a time when the slowly recovering economy needs both.

While the State Department has beefed up tourist services in recent years, reducing wait times significantly for would-be visitors will likely be a challenge as officials try to balance terrorist threats and illegal immigration with tight budgets that limit hiring.

"Security is job one for us," said Edward Ramotowski, managing director of the department’s visa services. "The reason we have a visa system is to enforce the immigration laws of the United States."

Anti-immigration proponents argue travel to the U.S. is already too accessible and that allowing more visitors would put the nation at greater risk.

"Everybody would like to find a way to admit as many people as possible to visit here providing that they visit and then go home," said Jessica Vaughan, director of policy studies at the Center for Immigration Studies, an anti-immigration group based in Washington, D.C.

"A lot of consular officers underestimate how much people want to come and live here," she said.

Nearly 7.6 million nonimmigrant visas were issued in 2001, compared with fewer than 6.5 million in 2010. The number of visa applicants also dropped sharply after 2001. Those combined forces pushed the U.S. share of global travelers down to 12 percent last year, from 17 percent before 2001.

The proposed immigration overhaul has largely been driven by the U.S. Travel Association, the tourism industry’s lobbying giant, and has been endorsed by business titans such as the National Retail Federation, Four Seasons Hotels and Resorts, and Walt Disney Parks and Resorts. Republicans and Democrats in Congress are backing the proposed changes through six bills in the House and Senate.

Geoff Freeman, the travel association’s chief operating officer, said the State Department should be required to keep visa interview wait times at a maximum of 10 days.

"Every day a person is waiting for that interview is a day a person cannot be here supporting the American economy," he said.

For most foreigners, taking a last-minute business or leisure trip to New York, Los Angeles, Miami or other U.S. travel hubs would be nearly impossible. The average wait time for a visa interview in Rio de Janeiro, for example, was 87 days, according to the State Department.

The Government Accountability Office, a nonpartisan agency that audits federal programs, concluded that wait times are likely much longer than reported because some department employees artificially reduce the wait times by not scheduling interviews during high-demand periods.

The vast majority of visitors enter through the country’s visa waiver program, which allows travelers from 36 nations with good relationships with the U.S. to temporarily visit without a visa. Travel proponents want to add nations whose residents are unlikely to illegally move to the U.S., including Argentina, Brazil, Poland and Taiwan.

Tourists from the rest of the world, including India, China, Mexico and other nations with affluent travelers looking to use their passports, must obtain a nonimmigrant visa. The process can be expensive and time-consuming.

People living far from a visa processing center must arrange travel to the interview location, not knowing whether they will be approved. Roughly 78 percent of all tourist visas were approved so far in 2011.

Tourism proponents want the department to embrace videoconferencing as a way to interview more people quickly. The department has no plans to implement videoconferencing interviews because of safety and technological concerns, Ramotowski said.

In-person interviews weren’t the norm before 9/11, when consular officials had the authority to approve travelers based on an application alone. Since then, however, screenings have become more strenuous, with fingerprint checks and facial recognition screening of photographs.

The State Department has made moves to boost its tourist services in recent years, transferring employees from underworked offices to bustling embassies and consular posts. Many visa processing centers are also operating under extended hours.

Other proposed changes include granting more multi-entry visas and charging premium fees to tourists who want a visa right away, similar to the premium passport fee charged to Americans with last-minute passport requests. The tourism industry also wants more visa processing officers and to allow travelers to submit applications in their native language.

"We can’t afford to treat them in a way that gives them an impression that maybe they aren’t welcome," said Rolf Lundberg, the U.S. Chamber of Commerce’s top lobbyist.

To help make the U.S. appear more welcoming, Congress approved last year a $200 million annual marketing campaign.

In Las Vegas, where travelers to the Strip have traditionally kept Nevada’s economy afloat, tourism and government leaders are desperate to keep businesses open and create jobs in a state with the nation’s highest unemployment rate.

"The industries affected by tourism are all behind it," said Republican Rep. Joe Heck of southern Nevada, who has sponsored a bill in the House that would require shorter visa interview delays, among other measures. "We need the jobs."

Ocampo, who spent her vacation shopping at upscale boutiques and visiting family in California, said she would be more eager to come back if she knew her business was wanted.

"Everyone wants to visit the Statue of Liberty and Disneyland," she said.