Senate Democrats want President Trump to disclose who's visiting the White House and Mar-a-Lago.

In letters Monday to Trump and the Secret Service, eight lawmakers urged the administration to extend an Obama-era policy of posting White House visitor logs online, and to include guests at the president's Florida resort.

Obama's White House began opening visitor logs to the public in 2009 after a legal settlement with a government watchdog group that had sued for access to them. The logs were released every three to four months.

"Continuing President Obama's transparency policies would help dispel concerns that the wealthy and the well-connected have unfair access to your White House," the senators wrote to Trump.

Related: Mar-a-Lago: Trump's Winter White House takes over Palm Beach

The letters were signed by Senators Sheldon Whitehouse of Rhode Island, Ron Wyden of Oregon, Jack Reed of Rhode Island, Tom Carper of Delaware, Tom Udall of New Mexico, Kristen Gillibrand of New York, Richard Blumenthal of Connecticut and Chris Van Hollen of Maryland.

Democrats also asked the administration to extend visitor disclosure reports to Trump Tower in New York.

Trump's repeated weekend trips to Mar-a-Lago have already drawn scrutiny from Democrats who say the exclusive club allows members to rub elbows with the president. Mar-a-Lago recently raised its initiation fee to $200,000, double the cost from a year earlier.

The Democrats' letter to the Secret Service also asked whether the agency is conducting security screening on Mar-a-Lago guests.

Related: Trump's Mar-a-Lago is getting more exclusive

Whitehouse and Udall asked Trump last month to make public the Mar-a-Lago membership and visitor lists. The administration did not respond, according to Monday's letter.

The White House and Secret Service did not immediately respond to requests for comment from CNNMoney.

The senators asked for a response by March 15.