Jordan has introduced new regulations to stem the flow of Iraqi refugees entering its territory.
The change will increase insecurity felt by refugees already in Jordan
The law states refugees fleeing the violence in Iraq must carry a new type of passport only available since 2006.
A BBC correspondent in Jordan says the law means its borders will be almost closed to Iraqis, hundreds of thousands of whom have already fled to Jordan.
The new G-Series passports are issued only in Baghdad, and are often only obtainable in return for a large bribe.
Jordan has become safe haven for anything up to one million Iraqis, but in recent months the flow has been drying up as border regulations have been tightened, the BBC's Jon Leyne says.
Britain and the US have also stopped recognising the old S-Series passports, which they say are easily forged.
Our correspondent says the measure will increase the feeling of insecurity shared by many Iraqis in Jordan, and many will fear leaving the country in case they will not be allowed back.
An Iraqi who arrived in Jordan at the end of 2006 spoke to the BBC News website about the change in Jordanian regulations.
"I don't think my parents will be able to join me here now because of this decision. My parents have old passports, which means there are restrictions on where they can travel," Amar Abdulla, a translator, said.
The United Nations has been trying to press for greater international involvement to manage the problem of Iraqi refugees.
There are thought to be about four million Iraqis living as refugees or internally displaced within their own country.
In addition to those in Jordan, there are another million refugees in Syria, which introduced its own stricter rules on residency for Iraqis earlier this month.
In both countries the influx has triggered prices rises in housing and goods and overcrowding in schools.