The motorcade carrying President Trump pulls out of his Mar-a-Lago estate on March 19. (Mandel Ngan/AFP/Getty Images)

A government watchdog agency, the Government Accountability Office, has agreed to review the costs and security precautions associated with President Trump’s travel and stays at Mar-a-Lago after a request for inquiry from leading Democrats on Capitol Hill.

On 17 days of his presidency, Trump has spent at least part of his time at Mar-a-Lago, his club in Palm Beach, Fla., flying down five times on Air Force One and requiring protection from the Secret Service, the U.S. Coast Guard and local police forces while in Florida. The government has not disclosed the costs.

After Trump announced his third trip there last month, Sens. Elizabeth Warren (D-Mass.), Sheldon Whitehouse (D-R.I.) and Tom Udall (D-N.M.) and Rep. Elijah E. Cummings (D-Md.) wrote to GAO chief Gene L. Dodaro, saying they were “deeply concerned” about the potential costs, as well as reports that Trump had met the Japanese prime minister in plain view of diners at the club.

[Nearly 1 out of every 3 days he has been president, Trump has visited a Trump property]

The Democrats also questioned whether the president’s company, which he still owns and which owns Mar-a-Lago, was charging the government “fair and appropriate” rates for use of the property while there at the service of the president.

The Washington Post's Jenna Johnson and Aaron Blake explain why President Trump spends so much time at his Mar-a-Lago resort in Florida, and how he uses it as a second White House. (Peter Stevenson/The Washington Post)

On Friday the GAO agreed to take up the inquiry by looking into four areas:

1) What measures are being used to protect classified information and provide secure communications capabilities while the president is away from the White House and whether a secure communications space has been created at Mar-a-Lago.

2) The type of security screening the Secret Service employs for guests and visitors of Mar-a-Lago.

3) What measures the Secret Service and Defense Department have taken to ensure the fees they are charged for Mar-a-Lago trips are “fair and reasonable.”

4) Whether the U.S. Treasury has received any payments resulting from profits at hotels that are owned or operated by the president.

The final two items relate to the president’s company, the Trump Organization, from which Trump has resigned his positions but where he is still owner. Trump’s adult sons, Eric and Don Jr., run the company, and to avoid conflicts of interest, the firm pledged recently to donate any profits from foreign companies to the U.S. Treasury at the end of each calendar year while Trump is president.

Trump has called Mar-a-Lago his “Winter White House,” and White House press secretary Sean Spicer recently countered criticism of Trump’s travel there.

[Trump family’s elaborate lifestyle is a ‘logistical nightmare’ — at taxpayer expense]

“The president is very clear that he works seven days a week. This is where he goes to see his family. He brings people down there. This is part of being president,” he said.

Though federal agencies have repeatedly declined to disclose the costs of the trips, in a previous report the GAO estimated that a similar trip President Barack Obama took to Florida cost about $3 million.

The Secret Service also requested $60 million extra for Trump-related costs and protection, according to internal agency documents, about half of that for security at Trump Tower, in New York, where first lady Melania Trump and son Barron Trump live.

Drew Harwell and Amy Brittain contributed to this report.