According to a statement by the central bank, the exchange reserves, however, increased 0.7 percent in the week between Dec. 28 and Jan. 3.
Morocco's dirham dropped 0.13 percent against euro and 0.21 percent against U.S. dollar.
The drop in Morocco's foreign reserves comes as the country plans to move to gradually float dirham.
The central bank had originally announced that the first step to float the currency would start in July.
However, the Moroccan government decided to delay the move, saying studies are being carried out to ensure enough time for the decision to take effect and to better understand "its impact on the economy and, in particular, on the purchasing power of citizens."
International Monetary Fund has vowed its backing to Morocco's move.
Currently, the dirham is fixed via a peg that is 60 percent weighted to euro and 40 percent to U.S. dollar.
The first stage will ease that peg to allow the currency to trade in a narrow range, which will expand gradually over a few years.