KUBEKHAZA, Hungary — As mayor of this Hungarian village where tens of thousands of migrants recently marched toward northern Europe, Robert Molnar has some sympathy for his country’s decision to build a fence on the border with Serbia.

But Molnar has a message for Americans: Don’t let President Trump build his wall with Mexico.

“We have a serious immigration issue. Europe is not prepared. It is important to protect our sovereignty. I accept that,” said Molnar, 47, sitting in his office in Kubekhaza, a short distance from the point where the boundaries of Hungary, Romania and Serbia meet.

“It serves no purpose other than political theater. It should come down. I would urge Americans to examine whether Trump’s wall will really make them safer or better off,” Molnar said.

He pointed out that Hungarian Prime Minister Viktor Orban, a staunch anti-immigration nationalist who easily just won a third term, had ordered $1 billion in electrified fencing equipped with cameras and heat sensors to keep out migrants.

Orban referred to refugees as “Muslim invaders” and vowed during the election campaign to protect Hungary from the “rust” of Muslim immigration.

“Orban decided we needed this wall. And that is the only reason we have it,” Molnar said. “If migrants want to come to Kubekhaza, for example, all they have to do is simply walk here from (neighboring) Romania, where there is no wall.”

Since the start of Europe’s migrant crisis in 2015, at least 800 miles of fences have been erected by Austria, Bulgaria, Greece, Hungary, Macedonia, Slovenia and others — a swift and concrete reaction as more than 1.8 million people descended on Europe from war zones from Afghanistan to Syria.

The length is about 40% of the 2,000-mile wall Trump wants built between the United States and Mexico to keep out illegal immigrants. About 700 miles of fencing already exists.

A recent visit by USA TODAY to Hungary and Slovenia — the two countries with the region’s largest expanse of fences — revealed that those who live and work near these barriers often find they serve little purpose and can be psychologically damaging. It’s a verdict with significance for Americans as Trump pushes his signature campaign promise: Build a wall and make Mexico pay for it.

Orban’s 20-foot-high, barbed-wire fence that stretches for 200 miles was built to block migrants from streaming through Hungary on their way northern Europe from Greece. It ends abruptly at the border with Romania to the northeast.

Molnar said the barrier will impact a generation of students.

 “We run a summer camp in this village, but more and more parents say their kids are scared to come here because of our proximity to the fence,” the mayor said.

“They think Kubekhazais a dangerous place because of the migrants. Yet we have no migrants here anymore, and the wall is not doing anything. It’s like a monument,” he added.

About 300 miles west of Kubekhaza, in Slovenia, hotel owner Peter Madronic copes with the nearby fence his nation built on the border with Croatia.

Madronic, 28, runs a guesthouse in a river valley popular with kayakers and mountain bikers. Slovenia preserved his hotel’s access to the Kolpa River — the natural border between Slovenia and Croatia — by building the fence around his land instead of directly next to the river. Doing that means his hotel is technically not in Slovenia nor in Croatia, less than 100 feet away.

“For some, it seems we are no longer in Slovenia, that we have been ‘fenced out,’ ” Madronic said, eyeing the 12-foot-tall chain-link fence. “Thankfully, the fence is not so ugly,” he said, adding that the barrier has not hurt his business.

Authorities claim Europe’s anti-immigration barriers accomplish what they set out to do: Keep people away.

Hungary said the fences helped cut migrants on its borders by nearly 100% since 2015, along with a deal made by Turkey and the European Union to stem the flow of migrants reaching the continent.

In the first three months of 2018, just 635 migrants were detected in the western Balkans — Albania, Bosnia and Herzegovina, Croatia, Kosovo, Macedonia, Montenegro and Serbia — trying to reach European countries farther north, according to the International Organization for Migration, a United Nations-affiliated group.

Last year, 200,000 migrants landed in Europe, way down from the nearly 2 million in 2015, according to Frontex, the EU border agency.

The barriers have brought fresh complaints and concerns. Scientists worry about the possible long-term effect on wildlife, such as brown bears, which can migrate across as many as nine countries in Europe.

“The fences are a real threat to them,” said biologist Djuro Huber at the University of Zagreb in Croatia who studies wildlife on the Slovenian-Croatian border.

And many in this region were baffled about inconsistencies and gaping holes along the borders.

“I don’t know why there are so many gaps in the fence,” Marija Grdesic, 32, said while guarding a narrow, wooden bridge that separates Croatia from Slovenia. “Perhaps it’s so local people can still reach the river to swim here,” she said, motioning toward the Kolpa River.

Emile Farran, 77, who works on a vineyard in Slovenia’s Istria region, pointed to an opening the length of a football field in the 15-foot-high fence topped with barbed wire intended to secure Slovenia’s border with Croatia.

“There is no need for this thing,” he said. “This is not a place where strangers ever pass. If the government really wants to help people like me, it should think about buying us some new tractors.”

These fences built in Europe differ from the one Trump wants along the Mexican border, said Ema Zuagen, 65, a retired physical therapist having coffee in Sevnica, Slovenia, the hometown of first lady Melania Trump.

“The thing about Trump’s wall is that it would keep out Mexicans and South Americans, who are mostly Catholic,” said Zuagen, who approves of the barriers. “Whereas our walls are keeping out immigrants who are mostly Islamic. There is a big difference.”