The most expensive property to protect is Trump Tower, which costs up to $197,000 a day. Credit:AP In the federal budget compromise reached last week, Congress allocated the Secret Service an additional $13 million ($A17.5m) to cover unanticipated overtime for its agents. It also set aside an extra $61 million ($A82.5m) to reimburse New York and Palm Beach for some of their expenses incurred since the election to protect the first family. "Although the federal government does not otherwise reimburse costs of state or local law enforcement for activities in support of the United States Secret Service protection mission, these funds are being provided in recognition of the extraordinary costs borne by a small number of jurisdictions in which a residence of the president is located," the budget bill stated. The jump in costs is largely due to the fact that Trump has used three separate residences - the White House, Trump Tower and Mar-a-Lago. Over the weekend he added a fourth: the Bedminster, New Jersey, golf club where the family has traditionally spent summer weekends. In addition to protecting the president and first lady, the Secret Service guards five children, their three spouses and eight grandchildren - 16 people in all. Since the election, Secret Service agents have accompanied the president's two adult sons on business trips to Dubai, Uruguay, the Dominican Republic, Canada, Ireland and Scotland. Each "protectee" - as they are called by the Secret Service - gets his or her own security detail even when travelling together.

President Donald Trump boards Air Force One. Credit:Evan Vucci When Melania, Barron and the president's younger daughter, Tiffany, recently visited Chelsea Piers, a sporting complex in Manhattan, 14 Secret Service vehicles waited outside. And when Donald Trump Jr., wife Vanessa and their five children; Ivanka Trump and her three children; and Eric Trump, wife Lara and their two beagles went to Aspen, Colorado, for spring break, they were accompanied by up to 100 Secret Service agents. Ski rentals for agents cost taxpayers $12,208, according to a government invoice uncovered by NBC News. Ivanka Trump is surrounded by police and security as she visits the Memorial to the Murdered Jews of Europe, at the Holocaust Memorial in Berlin. Credit:Markus Schreiber The most expensive property to protect is Trump Tower, the 58-story skyscraper in midtown Manhattan where Melania and Barron live in a penthouse and Donald Jr. and Eric have their offices.

The New York Police Department wrote in a letter to Congress that it was spending $127,000 ($A171,000) to $146,000 ($A197,000) a day to secure the building, in addition to the $4.5 million that the Fire Department expects to spend this year on security there. The costs are expected to decline after Melania moves to Washington this summer. One guest compared security at Trump Tower to that of US airports. Credit:Andrew Harnik Jonathan Wackrow, a former Secret Service agent who had been assigned to former first lady Michelle Obama, says the costs are justified because the security of the first lady has a direct bearing on the president's ability to function. Even so, Wackrow said: "It's an astronomical expense. You have to set up a massive security structure for the first lady to operate outside of Washington with everything that support the detail, from cars to communications. "New York is a very complicated environment," he added. "It's not like you're working in Billings, Montana."

On a weekday afternoon, cool and drizzling with nary a protester in sight - what should pass as a quiet day at Trump Tower - the building is a veritable fortress girded by at least 30 uniformed NYPD officers and at least that many Secret Service agents in bulletproof vests inspecting bags or guarding the elevators and doors. There also is a fleet of two dozen armoured SUVs, mobile police stations, police cars and other vehicles, including a strategically placed garbage truck that blocks the private garage through which members of the Trump family enter and leave the building. More security forces are tucked away in the surrounding high-rises. Mar-a-Lago is another big expense. Palm Beach County says its overtime runs $60,000 ($A81,000) a day when Trump is visiting, and was $250,000 ($A338,000) for the weekend when Chinese President Xi Jinping joined him. The county is considering turning the Mar-a-Lago resort into a special taxing district to recoup the money being spent on Trump. Since taking office, Trump has spent seven weekends at the resort, each trip costing at least $1 million ($A1.35m), with some estimates running up to $3.6 million ($A4.8m). The biggest chunk of that is the $142,000 ($A192,000) an hour it costs to fly Air Force One. Melania Trump has flown separately on five occasions either to or from Palm Beach, according to the Palm Beach Post. Public accounts of her appearances show she has also made at least eight round-trip flights to Washington, D.C., since the inauguration. The Air Force said that it could not immediately provide her flight records but that each hour of flying on the Boeing C-32 - the largest and most expensive of the three planes she uses - costs $38,922.

"It is all about security," Wackrow said. "The first lady needs to be in constant communication with the president and she has no ability to do that on a non-military aircraft." More controversial is the foreign travel of Donald Jr. and Eric, who make frequent splashy trips to Trump-branded properties. "You have people with not only heavy travel schedules, but heavy business schedules with enormous public profiles," said Dan Bongino, a former Secret Service agent who is now active in Republican politics in Florida. "Donald Trump Jr. is like a brand in and of itself." Fireworks lighted up the sky over Dubai in mid-February when the Trump brothers hosted a private party for 1,500 people to open the Trump International Golf Club, events that were guarded at the expense of US taxpayers. The costs have not yet been made public, but a shorter trip by Eric Trump to promote a Trump Tower in Punta Del Este, Uruguay, ran up $97,830 in hotel bills for Secret Service agents, State Department personnel and local law enforcement officials, according to government records found by The Washington Post. A former Secret Service agent said a trip of that type would have required at least 20 agents - field officers, intelligence officers, day- and night-shift agents, and drivers - and that they might have gone ahead by two weeks to prepare. Secret Service agents are reimbursed for food and lodging at the State Department daily rate, which for Dubai, United Arab Emirates, is up to $553 ($A748).

"You don't want a family member of the president to go unprotected, but what you really have here are ... taxpayers subsidising Trump's business activity," said Norman Eisen, who served as ethics czar under Obama and now heads the watchdog group Citizens for Responsibility and Ethics in Washington. Loading The cost of protecting Obama and his family during the previous administration drew the ire of Republican columnists and politicians, including Trump. "President @BarackObama's vacation is costing taxpayers millions of dollars - Unbelievable!" he tweeted in January 2012 while the Obama family was visiting Hawaii. Los Angeles Times