WASHINGTON — The Justice Department said in a court filing this week that Hillary Rodham Clinton had the authority to delete emails that she did not believe were government records from the personal account that she exclusively used while secretary of state.

The statement was made in connection with a lawsuit brought by the conservative group Judicial Watch. The group is seeking to force the government to search the server that housed Mrs. Clinton’s account for messages related to a video ad the State Department aired in Pakistan. Judicial Watch contends the ad was an apology for the Internet video that the administration initially blamed for inciting the 2012 attacks on the American diplomatic compound in Benghazi, Libya.

Mrs. Clinton has given the State Department roughly 30,000 emails from the account that she determined were government records. She has said that she deleted about 31,000 other emails that she said were personal, and Justice said that those are not government records.

Under federal record-keeping guidelines, government employees are “required to review each message, identify its value, and either delete it or move it to a record-keeping system,” the Justice Department said.