A woman suspected of sending a package containing the poison ricin to the White House has been arrested at the U.S.-Canada border in New York, according to authorities.

The package, addressed to President Donald Trump, was intercepted by federal authorities in the past week, a law enforcement official said Saturday. The woman was taken into custody by U.S. Customs and Border Protection officers at the Peace Bridge border crossing near Buffalo and is expected to face federal charges, three law enforcement officials told The Associated Press on Sunday.

NBC News also reported the woman's arrest, citing a federal law enforcement official. Her name was not immediately released.

The FBI, in a brief statement, described the missive as "a suspicious letter received at a U.S. government mail facility."

"At this time, there is no known threat to public safety," the FBI said Saturday.

Mail addressed to the White House is screened at an off-site location. The letter's discovery was first reported by CNN.