Education Secretary Betsy DeVos spoke last month during a student town hall in Philadelphia. Annual security costs for the secretary, who frequently travels to meet with students and teachers, are expected to increase by about $1 million from last year's level. (Matt Rourke/AP)

The cost of providing U.S. marshals to protect Education Secretary Betsy DeVos is expected to rise to $7.7 million this year, a nearly $1 million annual increase but an expense “commensurate with the existing threat” against DeVos, the U.S. Marshals Service said this week.

The Education Department signed an agreement with the U.S. Marshals Service that went in to effect Sunday, the start of the fiscal year. The agreement, first reported by Politico, includes round-the-clock protection for the secretary, who frequently travels to schools across the country and sometimes travels internationally for her job.

DeVos is the first education secretary and the only Cabinet member to receive protection from U.S. marshals. The marshals are typically responsible for apprehending fugitives and guarding judges and witnesses. Previous secretaries were protected by an Education Department security team, which included Secret Service veterans.

While DeVos’s security arrangement is unprecedented, so, too, is the vitriol she faces. Her advocacy for charter schools and private-school vouchers and her lack of public school experience have made her a polarizing figure, and she has faced boisterous protests during school visits and speeches. A yacht owned by her wealthy family was recently untied from a dock in Ohio, sending it adrift on Lake Erie. The stunt led to $5,000 to $10,000 worth of damage to the boat.

The secretary used the in-house security team for the first days of her tenure. But during her first school visit, to Jefferson Middle School Academy in the District, protesters confronted her and blocked her from entering. Her security team rushed her back to a waiting vehicle and whisked her away so she could use a different entrance. Soon after, she sought protection from the Marshals Service.

The Education Department paid the Marshals Service $6.79 million for security during the past fiscal year, which ended Sep. 30.

In a statement, the Marshals Service said: “The number of [Marshals Service] personnel assigned to the detail is commensurate with the existing threat and based on [Marshals Service] protective service requirements, experience and methodology.”

Asked why the costs were rising, Education Department spokeswoman Liz Hill said, “The level of protection is assessed regularly and is commensurate to the threat level.”