Top Senate Democrats have asked the FBI to assess the possible threat to national security posed by President Trump's Mar-a-Lago resort after a woman with Chinese passports allegedly managed to deceive her way onto the property Saturday with a malware-infected device.

Sens. Chuck Schumer, Sen. Mark Warner, and Sen. Dianne Feinstein have sent a letter to FBI Director Christopher Wray asking the FBI to "assess the risk at Mar-a-Lago posed by establishment of areas for classified information at facility accessible to the public and foreign nationals." House Oversight and Reform Chairman Elijah Cummings and Ranking Member Jim Jordan will also be briefed on the matter, which has renewed security concerns about the president's "winter White House."

Yujing Zhang is being held in the Palm Beach County Detention Center in West Palm Beach, according to law enforcement sources, after she was charged with making false statements to a federal officer and entering a restricted facility. On Saturday, according to a criminal complaint filed in the Southern District of Florida, 32-year-old Zhang made it through checkpoints and all the way to the main reception area of the Mar-a-Lago club before she was stopped from going any further when a receptionist determined she wasn't on an approved guest list. Secret Service agents did halt her at multiple points to question her purpose for being there.

Get Breaking News Delivered to Your Inbox

Mr. Trump was in West Palm Beach Saturday, although he was at his golf course away from Mar-a-Lago when the alleged incident began. The president left Mar-a-Lago for his golf club at 9:37 a.m., according to pool reporters traveling with the president at the time. The complaint says Zhang was first confronted on the property at 12:15 p.m. Mr. Trump returned to Mar-a-Lago at 3:56 p.m.

On Wednesday, the president said he wasn't concerned by the incident.

"I saw the story. I haven't spoken to anyone," the president said during a meeting with senior military leaders. "We have extremely good control."

"The person at the front desk did a very good job, to be honest with you," he added.

According to the complaint, Zhang changed her reason for being on the premises, and falsely told the Secret Service she was a Mar-a-Lago club member. And then, after claiming she wanted to access the pool, she said she was actually at Mar-a-Lago to attend a non-existent "united Nations Friendship Event" between the U.S. and China.

According to the Secret Service, Zhang had no swimming apparel in her possession. But she was in possession, according to the court filing, of four cellphones, one laptop, one external hard drive and one thumb drive containing "malicious" malware.

Read more on Mar-a-Lago:

The criminal complaint says Zhang claimed to federal authorities a Chinese friend "Charles" told her to travel from Shanghai to Florida to attempt to attend the non-existent event and speak with a member of the Trump family about U.S.-China relations. Zhang claimed she spoke with "Charles" on "WeChat," a messaging platform common in China.

The Secret Service explained in a statement Tuesday evening that the Mar-a-Lago Club, where the president spends several weekends and holidays in the winter and early spring, is treated like "any other site temporarily visited by the President" or anyone else under Secret Service protection.

While Mar-a-Lago staff transported Zhang between screening checkpoints, the Secret Service conducted the screenings and monitored the route between checkpoints. Once the reception staff realized that Zhang "should not have been authorized access," Secret Service agents immediately arrested her.

If convicted, Zhang faces up to six years in prison. Her preliminary arraignment is scheduled for April 15. Zhang's attorney, a public defender, declined to provide any additional information to CBS News.

— CBS News' Sara Cook, Julia Kimani Burnham, Rebecca Kaplan and Arden Farhi contributed to this report.