Sen. Tom Carper sent a follow-up letter on May 24 to Department of Defense Secretary James Mattis regarding serious security concerns related to President Donald Trump’s reported use of an unsecured smartphone.

In February 2017, Carper wrote to Mattis to gain a better understanding of the efforts by the Department of Defense and the White House to oversee, develop and implement protective measures for Trump’s use of a smartphone. The Department of Defense, through the Defense Information Systems Agency and the White House Communications Agency, provides direct services and communications support to the president and his staff. More than 15 months later, the department has yet to respond to this important matter.

Additionally, the issue remains a serious security risk as recent reports indicate the president continues to deviate from long-established diplomatic protocols and security measures concerning his external smartphone communications.

“Just this week, a new report indicates that ‘President Donald Trump uses a White House cellphone that isn’t equipped with sophisticated security features designed to shield his communications…a departure from the practice of his predecessors that potentially exposes him to hacking or surveillance.’ This is all the more concerning in light of reports indicating that President Trump has urged world leaders to contact him directly through his smartphone and that White House Chief of Staff John Kelly’s personal smartphone was compromised for months,” wrote Carper.

Carper requested that Mattis respond to his latest request no later than June 8.

The full letter can be found at