US president Donald Trump’s four adult children and their spouses have joined him on his state visit to the United Kingdom this week. And US taxpayers are picking up the hefty bills for their hotels, transportation, and security.

Ivanka Trump and her husband Jared Kushner, Eric Trump and his wife Lara, Donald Trump Jr. and Tiffany Trump were all among the 171 dinner guests at Buckingham Palace today, according to the White House press pool.

Guests dined on Windsor lamb, steamed halibut, and watercress mousse, while they listened to Handel’s “Music for the Royal Fireworks” and “Tonight” from West Side Story. Wines included a 1990 Chateau Lafite-Rothschild Pauillac, which retails for $1,500 a bottle, and a more reasonable £35-a-bottle ($44) British bubbly from the Queen’s own vineyard.

Attendees comprised a mix of royals, politicians, and business executives. Trump’s entourage included Treasury secretary Steven Mnuchin, his wife Louise Linton, National Security Council advisor John Bolton, and presidential counselor Kellyanne Conway.

Critics have questioned the timing and reason for the trip, given Britain’s state of flux over Brexit and the fact that prime minister Theresa May (another dinner guest) is stepping down in a matter of days.

While the Queen paid for the dinner, US taxpayers will spend millions on the trip, according to a Quartz analysis of expenses available in the federal government’s publicly accessible databases. This tally doesn’t include the cost of security, ground transportation, or airfare for many of the US attendees.

$1.3 million to a Qatari-owned luxury hotel

The president and some of his delegation appear to be staying at the Intercontinental Park Lane Hotel, where the US embassy in London is spending more than $1.3 million on rooms. The Qatari sovereign wealth fund bought the hotel in 2013, and it is controlled by Constellation Hotels, which is owned by Qatar Holding.

The hotel, located just between Buckingham Palace and Hyde Park, features a “Royal Suite” and adjoining group of rooms that “pay homage” to the hotel’s location at 145 Piccadilly, Queen Elizabeth II’s childhood residence.

parklane.intercontinental.com The bedroom in the Royal Suite.

The suite cost an estimated £10,000 ($12,660) a night in 2017.

$1.1 million on other London hotels

US taxpayers are paying another $1.1 million for 10 additional contracts with other hotels in London, most of them near Buckingham palace. That includes:

$339,000 at the London Hilton on Park Lane, a 450-room tower that has a Polynesian-themed Trader Vic’s bar in the basement.

$92,000 at the Cumberland Hotel at Cumberland Place.

$37,000 at the Hyatt Regency Churchill hotel, named after the former prime minister.

More than $2 million on Air Force One

As Quartz reported last year, it costs $14,406 for Trump and the first lady to make the 10-minute trip aboard the presidential Marine One helicopter to Joint Base Andrews, the Maryland Air Force installation where the government parks Air Force One. Flight time from Andrews to London aboard the customized Boeing 747 is 7 hours and 25 minutes, which translates to a one-way cost of just over $1 million, according to the official Department of Defense rate of $142,380 per hour.

The return trip clocks in at 8 hours and 10 minutes. That’s a cost of about $1.15 million.

Trump’s kids didn’t travel on Air Force One, according to press pool reports. Instead, the president travelled with an entourage of about a dozen, including advisors Stephen Miller and Kellyanne Conway, and Treasury Secretary Steve Mnuchin.

Whichever way his children did fly, they’re likely to have been accompanied by Secret Service protection, whose airfare costs will be borne by taxpayers.

More than $200,000 on IT support

The US Department of State filed a $13,000 expenditure for “ANTENNA INSTALLATION IN SUPPORT OF A VIP VISIT,” presumably for temporary radio communications infrastructure. The recipient was not specified in government filings. Other beneficiaries of State Department largesse include Verizon UK, which is set to receive at least $200,000 for installing data circuits and lines, also “IN SUPPORT OF A VIP VISIT,” according to federal spending records.

Quartz was unable to locate any transportation expenditures on the government databases, although records sometimes appear weeks or even months after the fact. On past trips, taxpayers have picked up the Trump family’s tab for sundry items ranging from limousine service for Eric Trump to airfare and lodging for Eric and brother Donald Jr., to a $6,000 car rental “in support of” an unexplained trip Don Jr. took last year to Germany.