Chad has threatened to expel any more refugees arriving from Sudan's Darfur region, saying their presence is triggering insecurity.
Prime Minister Nouradine Delwa Kassire Coumakoye said the influx of refugees into eastern Chad risked becoming a 'bone of contention' between the two countries.
It has called on the international community to take refugees elsewhere.
Tensions are already high between N'Djamena and Khartoum after an assault by Chadian rebels based in Darfur on the Chadian capital just over a week ago.
Chad accuses Sudan's government of backing the rebels, a charge it denies.
'Chad can no longer support something so harmful to it. Refugees bring insecurity. Today, Chad is under attack from Sudan because of these refugees,' Mr Coumakoye said.
'We ask quite simply that they be moved. If not, we will do so ... Their presence is causing us problems. We have had enough. We will move them in the superior interest of our country. We can no longer continue to sacrifice our people.'
Thousands more refugees fled into Chad over the weekend to escape Sudanese army and militia attacks in west Darfur, underlining the urgency of a planned deployment by a European Union peacekeeping force (EUFOR) to eastern Chad.
EUFOR has a UN mandate to protect more than 500,000 refugees who have fled fighting in Darfur. But EU commanders suspended the deployment of the force during intense fighting in and around N'Djamena during the rebel assault at the start of February.
Meanwhile, N'Djamena airport today reopened for civilian traffic.
An Air France flight from Paris is due to land there tomorrow morning. The French company plans initially to make four of its usual seven weekly scheduled flights.
