By Cagil KasapogluReporting fromLos Angeles and Sakshi VenkatramanReporting fromNew York

Many international fans visiting the US for the World Cup have become frustrated by the culture of tipping servers, telling the BBC that tipping fatigue has set in.

England supporter Geoff Pryor said he understood tipping for good service, but he found it "weird" when buying a bottle of water and "they try to get a tip for doing nothing".

In the US, staff at some restaurants and bars are paid just over $2 (£1.50) an hour, and they expect customers to tip about 20% of the total cost of the bill so they can earn a living.

Frustrations have also been shared by hospitality staff, with one bar owner telling the BBC that many World Cup tourists have been bad tippers.

Australian supporters Chris O'Flynn and Robert McNamara told the BBC that high ticket prices for football matches have drained their finances, and paying tips is driving up expenses.

"I still find it a bit confusing why it exists... In Australia you have a flat fee, and you pay it. Here people ask for, or expect, tips. Sometimes you don't know how much you're supposed to tip," O'Flynn said.

"The way most Australians here feel is: Pay your staff a better wage. It should be on the business, not the customer, to make sure that your staff is well paid."

McNamara said they try to "abide by the customs" as visitors, but tipping has been a culture shock.

"They're expecting a tip after every drink so it gets expensive very quick. You're buying a drink and adding $5 on. It's difficult to comprehend."

Fan says the prices without tips are already expensive

Pryor, an England supporter from Norwich, is travelling around the US for the tournament. He said despite his frustrations at being asked to tip for a bottle of water, he did understand the need to tip at restaurants.

"I appreciate they're not paid as much as perhaps back in the UK, but overall the service is generally good, so when it's good they deserve a good tip," he said.

Maiko Asahi and her family are visiting from Tokyo to watch Japan play in Dallas, and told the BBC that tipping is not something they do back home. "The prices without the tips are already very expensive, with tipping it is way too much," Asahi said.

Another Japanese fan, Akihiro who is travelling with his son, also complained about high prices.

"Even the cheapest meal at a restaurant still costs around $30, and when you add on a tip of say, 13-20% you end up thinking - Oh dear, I could have had another portion for that," he said.

Europeans don't tip like Americans, bar owner says

Banter, a football bar in Brooklyn, sees its fair share of British and European tourists - especially during the World Cup.

But they are notoriously bad tippers, if they tip at all, owner Chris Keller told the BBC.

"It's always the case. There's no getting around it," he said. "There's always a lack of tipping or playing ignorant like they don't know."

Keller said he's changed the system so customers with reservations have to pre-pay for drinks, including a service charge. "It's just to protect our staff," he said.

Hurley's Restaurant & Bar in New York City has had massive foot traffic at a time of year that would normally by quieter, co-owner Ann Calimano said. But not all of the new customers are used to tipping.

"Europeans don't tip like the American people," she said. "That's the culture."

She said when customers order $600 (£455) worth of food and drink without tipping the servers, a conversation is necessary.

"The bartenders will graciously ask, 'was the service okay?' and they'll say 'yes, of course,'" she said. "And then they'll explain that the service is not included, whereas in Europe, the service is included in the price of everything."

It's impossible for staff to survive without tips, restaurant owner says

In Los Angeles, California, the base wage for tipped employees is among the highest in the country at $16.20 per hour.

Joseph Pitruzelli, owner of Wurstküche, a German-themed restaurant in Downtown LA, said they have not seen much difference in tipping habits during the World Cup.

"We keep our [suggested] tips as low as in the 10, 15 and 20% range but I've seen some places suggest 20, 25 and 30%, which I think is really high," he said.

"We share the tips amongst everybody on the team that goes into making the experience great, from the dishwashers that make sure that the dishes are clean to the chefs in the kitchen and to the bartenders and servers."

Rosa Thurnher, owner of El Ponce restaurant and a board member of the Independent Restaurant Coalition, said businesses have noticed changes in tipping behaviour since World Cup fans arrived.

"It's very different around the world, but in the US it is unique the amount of tip that is expected in our industry. For here, 20% is pretty standard," she said.

"And that is mainly due to the fact that the minimum wage and wage structure is very different here."

For instance in Atlanta, the minimum cash wage for a tipped server is $2.13 per hour. If tips combined with wages do not reach the state minimum of $7.25, the employer must make up the difference.

"If they don't receive any tips, it's impossible to survive in the service industry," Thurnher said.

And while US states can legislate for restaurant workers to be paid more, tips are seen by the US government as a core - and expected - component of such employees' income.