Chinese officials have asked the United States to restrict imports of a wide range of artifacts from the prehistoric period through the early 20th century because they believe that demand in the United States for Chinese antiquities has helped fuel a sharp increase in looting of archaeological sites and even thefts from museums over the past several years.
Currently, U.S. Customs officials can reject the importation of items from China that are suspected of having been stolen or looted, but, in practice, relatively few items are seized.
Recently, China has stepped up efforts to reclaim cultural relics that have been stolen and brought to other countries. In related news, the Asian Art Fair is now going on in New York.