"Fifteen thousand objects are still missing from the Iraq museum," which was looted at the end of the US-led war last year, Donny George told reporters in Amman on Tuesday.
"We are sure that Iraqi antiquities are going out through Turkey and Iran," he said.
George was speaking on the sidelines of a two-day meeting of customs officials from several of Iraq's neighbours, as well as US and European law enforcement agents.
He said some of Iraq's neighbours, including Jordan, Syria, Kuwait and Saudi Arabia had cooperated with Baghdad and seized hundreds of items smuggled through their borders in the aftermath of the invasion to oust Saddam Hussein.
The director-general of Jordan's department of antiquities, Fawaz Khraysha, said more than 1000 stolen objects had been seized and were being held in safekeeping until the Iraqis request their return.
"We have around 1046 objects, various ones. They have been listed on CDs and copies have been given to Iraq and to UNESCO," the UN cultural agency, Khraysha said.
The US is criticised for 'not doing
much' to protect the museum
George said Syria was holding in safekeeping about 200 artefacts looted during the war while Kuwait managed to retrieve 35 objects stolen from the museum.
"Saudi Arabia told us they have objects but we don't know exactly how many. We are in contact with them through the ministry of foreign affairs," George said.
He added that these countries should hold on to the items until stability returns to Iraq. The missing items include a half-sized, headless statue of Sumerian king Entemena made of diorite as well as an important ivory and gold plaque known as the Lioness and the Nubian, which is inlaid with precious stones.
Artefacts are still being taken from the country's archaeological sites.
"Looters are digging as we speak and we can't do anything about it," said George.
He complained that the occupation forces were not doing "that much" to stop the looting because "they have, as they say, other priorities such as security, water, electricity".
"We are sure that Iraqi antiquities are going out through Turkey and Iran"
head of Iraqi National Museum
Iraq is planning to set up a 1300-strong antiquities police force and is looking for vehicles to patrol the country's numerous archeological sites.
However, according to a senior Interpol agent, Karl Heinz Kind, policing is hampered by the fact that there are 100,000 archeological sites in Iraq but only 10,000 are registered.
"This makes it impossible to protect all of them and the major problem we are now facing is the continuous looting of Iraq's archeological sites," Kind said at the start of the meeting.