No amounts authorized to be appropriated to the Department of Justice under this title or an Act amended by this title may be used by the Attorney General, or by any individual or entity awarded discretionary funds through a cooperative agreement under this title or an Act amended by this title, to host or support any expenditure for conferences that uses more than $20,000 in funds made available to the Department of Justice, unless the Deputy Attorney General or the appropriate Assistant Attorney General, Director, or principal deputy (as designated by the Deputy Attorney General) provides prior written authorization that the funds may be expended to host the conference.