By Julia Harte

WASHINGTON (Reuters) - Democratic U.S. lawmakers on Monday urged President Donald Trump to release logs of visitors to the White House and Trump's Mar-a-Lago resort in Florida under a policy that made public the names of nearly six million visitors to the White House during the administration of Barack Obama.

If Trump continues the policy, under which visitor logs were released 90 to 120 days after they were created, the public could learn who has been visiting the Trump White House as soon as April 20, according to the lawmakers' letter.

Two of its eight signatories, Senators Sheldon Whitehouse and Tom Udall, received no reply to a Feb. 3 request that Trump publicize visitor lists from Mar-a-Lago, which Trump has described as the "Winter White House" and visited four times since becoming president, according to Monday's letter.

The White House did not immediately respond to requests for comment. A page on the White House website's "Disclosures" section entitled "Visitor Access Records" says the page will post records of White House visitors on an ongoing basis, once they become available. It does not mention Mar-a-Lago.

Photos taken by private guests at the Florida resort in February showed Trump and Japanese Prime Minister Shinzo Abe conferring after North Korea conducted a ballistic missile test, prompting a Republican-led congressional oversight committee to ask the White House whether security protocols were followed.

"One way to provide assurances that your Administration is listening to the voices of all Americans, not just friends and donors who have a financial self-interest to influence government policy, is to let everyone know who is meeting with you and your staff," Monday's letter to Trump read.

The senators sent a similar letter on Monday to William Callahan, deputy director of the U.S. Secret Service, asking how the agency will conduct background checks on people who will be present during Trump's trips to Mar-a-Lago, Trump Tower in New York City, Trump's golf resort in Bedminster, New Jersey, or other Trump properties where he may conduct official business.

The Secret Service declined to comment.

(Reporting by Julia Harte; Editing by Dan Grebler)