Mukasey will be the first attorney general since Janet Reno in 1996 to represent the government at the high court. Neither John Ashcroft nor Alberto Gonzales, President Bush's first two attorneys general, argued a case at the court.
Mukasey will ask the justices on March 25 to reinstate the conviction of would-be millennium bomber Ahmed Ressam on a charge that an appeals court threw out, Justice Department spokesman Peter Carr said.
The 66-year-old Mukasey is a former federal judge who presided over high-profile terrorism trials in New York.
The San Francisco-based 9th U.S. Circuit Court of Appeals overturned just one of the nine counts on which Ressam was convicted for plotting to bomb Los Angeles International Airport around Jan. 1, 2000. The charge in question is carrying explosives during the commission of another serious crime.
The appeals court said the law required prosecutors to show the explosives were carried "in relation to" the felony, which in this case was lying on a Customs form.
Mukasey will urge the justices to reverse the appeals court, in part because the ruling could make it harder to prosecute terrorists. The government argues that the law means a defendant must be carrying the explosives at the same time as he commits another crime.