An agreement between China and the United States to restrict imports of archeological items originating from China has been extended, Chinese authorities confirmed on Friday.

The extension has been approved by the State Council and confirmed via documents between the two sides, said a statement issued by the State Administration of Cultural Heritage.

The memorandum of understanding, first signed by the governments of the two countries in 2009, targets items that date from the Paleolithic period through to the Tang Dynasty, from approximately 75,000 B.C. to A.D. 907, as well as monumental sculptures and wall art at least 250 years old.

A new revised version took effect on Tuesday and will last for five years, according to the statement.

Revisions concern public awareness promotion, cultural heritage protection and preservation as well as communication and cooperation, law enforcement and information sharing, the statement said.

It said the revision and extension of the document is a significant step taken by China in curbing illegal transactions of cultural properties through inter-governmental cooperation within the framework of international conventions.