Applications from international students to the University of California have fallen for the first time in 12 years — reversing an era of robust global interest in the famed public institution, a Chronicle analysis shows.

The drop-off follows more than a decade in which the number of international applications rose by an average of 21 percent a year — or more than 2,500 annually — and coincides with the election of President Trump. UC’s application period for fall 2017 was the month of November 2016. Trump was elected on Nov. 8.

International undergraduate applications for next fall dropped by 1 percent from the prior year to 32,647, a decline of 353 requests. Applications from Mexico plunged by 30 percent. Countries with large populations of Muslims collectively sent in 10 percent fewer applications.

The last time undergraduates from around the world shied away from UC, the United States had just led a multinational invasion of Iraq in 2003. The war coincided with a plunge in international interest in UC campuses and other American universities in 2004 and 2005 that even post-9/11 security crackdowns had failed to achieve.

Now the phenomenon appears to be back — not only at UC, but at campuses across the country, according to a new national survey of 261 colleges and universities by the American Association of Collegiate Registrars and Admissions Officers. Nearly 40 percent of those schools reported a drop in international applications of at least 2 percent, with the greatest decrease from countries in the Middle East.

“The perception is that this administration wants to keep these students out,” said Melanie Gottlieb, the association’s deputy director. Admissions officers reported that would-be applicants expressed concerns about “negative rhetoric around the Muslim faith, and immigration changes — even before the (aborted) travel ban” from Muslim-majority countries, Gottlieb said.

Asked to respond, a representative from the U.S. Department of Education said only, “We can’t speculate.”

The UC application numbers analyzed by The Chronicle reflect undergraduates hoping to transfer in or start as freshmen. Graduate-level data were not immediately available — but many graduate students say they feel concern after the Trump administration’s two attempts to block citizens from several Muslim-majority countries. These students say they want to minimize their risks when they pick a place to study. So the idea of obtaining a student visa, then possibly learning their home country has been banned, is chilling.

Rozhin, 35, lives in Iran and spoke on condition her last name not be used. She has a master’s degree in fine arts and had hoped to apply to art schools in the U.S. this year. That’s changed.

“Applying to U.S. schools seems very risky to me because even if I get admitted and get a visa, I don’t know what might happen in the future and what new rules can surface,” she said in an email interview.

Some students from abroad fear they could get stuck if they returned home to visit their families.

“With the news around banning people from Iran and few other countries, I no longer can consider applying to U.S. schools because there are too many uncertainties and potential hardships when it comes to visiting my family,” said Shilan, 22, an Iranian who asked that her full name not be used. She said she’ll apply to graduate programs in the United Kingdom and Turkey instead.

About 1 million college students from other countries study in the United States, or 5 percent of the total enrollment, according to the Institute of International Education. The population has risen steadily for decades, but has soared by 41 percent since 2009.

California colleges host more of those students than any other state — about 150,000, the institute reports. Last fall, UC admitted 17,339 freshmen from other countries to its nine undergraduate campuses. The vast majority, 83 percent, came from 21 countries.

This year, in an unusual turn, fewer students in 15 of those countries applied to UC than last year. Seven of those countries — United Arab Emirates, Turkey, Malaysia, Indonesia, Saudi Arabia, Pakistan and the Philippines — have large Muslim populations. Collectively, applications from those countries dropped by 10 percent, to 1,561 from 1,727.

Also, fewer students are applying to UC from Mexico, a country Trump is seeking to literally wall off from the United States. Applications fell 30 percent since last year — to 98 from 140.

UC Berkeley saw a 1 percent drop in freshman applications from other countries after years of annual increases that ranged from 7 to 50 percent. UC Riverside’s international freshman applications also fell, by 2 percent. UC’s seven other undergraduate campuses had increases — but far fewer than in previous years. The increase at UC Davis, for example, was 3 percent for next fall, compared with 21 percent for last fall. A similar pattern repeated at the other campuses.

“The UC brand remains very strong” among international students, said Stephen Handel, the university’s associate vice president for undergraduate admissions, who said he wasn’t sure why international applications dipped this year.

“It’s really hard to tell at this point,” he said. “Of course, the national dialogue (about immigration) is out there. Students around the world read the newspaper. But there are other things in play.”

He said price might be a factor; UC recently increased the surcharge out-of-state residents pay by 5 percent, raising their annual tuition to $41,964 beginning this summer.

He acknowledged, though, that UC often raises its price, and global applications haven’t previously suffered.

Last year, when UC raised the surcharge by 8 percent, international applications still grew by 3,161. UC also increased the price by 8 percent the year before that, yet received 2,583 more international applications than the previous year.

Whatever the reason, Handel said, he’s focusing on who actually enrolls, not on who expresses interest. And students haven’t made those decisions yet.

But Gottlieb of the American Association of Collegiate Registrars and Admissions Officers said that looking at applications offers clues about what people around the world are thinking. Making them feel welcome confers unexpected benefits, she said.

“When international students go back home, they become ambassadors in their country for U.S. education — and for U.S. economic interests because they’ve had this positive experience in the United States,” said Gottlieb of the American Association of Collegiate Registrars and Admissions Officers.

But without them, there are negative side effects, she said. “We’ll lose the ability to capture that soft diplomacy.”

The loss of innovation is another potential problem. Many innovators in Silicon Valley and elsewhere are immigrants who studied at American universities.

Mamoon Hamid, 39, came to the United States from Germany as a teenager. Hoping to become an astronaut with NASA, he studied electrical engineering at Purdue University, a school that has produced nearly two dozen astronauts selected for space flight.

Although Hamid never became an astronaut, today he is co-founder and general partner of Social Capital, a Palo Alto venture capital firm that invests in health care, education and financial services companies.

If he were a teenager now, Hamid said, he would not apply to the United States.

“In the current environment,” he said, “I would say that America is a closed country — I’d stay in Europe.”

If many others do the same, Hamid said: “We lose innovation. We lose people who want the American dream. We need that.”

Hamed Aleaziz and Nanette Asimov are San Francisco Chronicle staff writers. Email: haleaziz@sfchronicle.com, nasimov@sfchronicle.com Twitter: @Haleaziz, @nanetteasimov