A French court has ordered the extradition of Rwandan rebel leader Callixte Mbarushimana to face trial at the International Criminal Court.
Mr Mbarushimana is accused of 11 counts of war crimes and crimes against humanity, committed in the Democratic Republic of Congo last year.
His ethnic Hutu FDLR group is at the heart of years of conflict in eastern DR Congo, near Rwanda.
Arrested in France last month, he has previously denied war crimes charges.
Mr Mbarushimana faces five counts of crimes against humanity and six counts of war crimes, including charges of murder, torture, rape, inhumane acts and persecution, and destruction of property.
The Paris court approved his transfer to The Hague's ICC "on condition that under no circumstances should Mr Mbarushimana be taken back by any means to Rwanda".
Some FDLR leaders have been accused of taking part in the 1994 genocide of ethnic Tutsis and moderate Hutus in Rwanda.
ICC spokesperson Pascal Turlan said that unless Mr Mbarushimana's lawyers appealed against the decision, he would be handed over to the court within a month.
His lawyers had tried to block the ICC warrant, arguing it could be a first step towards sending him back to Rwanda, where they say he would not get a fair trial.
But Mr Turlan said the defendant would be tried in The Hague.
"Mr Mbarushimana is under two arrest warrants in Rwanda and the fear of the defence was that this would be a kind of a smokescreen to actually send him to Rwanda," he said.
"Of course it's not the case. Of course the person is surrendered to the ICC to be tried before the ICC."
FDLR fighters were recently accused of raping hundreds of people in DR Congo, although the group has denied responsibility.
After a Tutsi-dominated group took power in Rwanda ending the genocide, Mr Mbarushimana's FDLR group fled into what is now the Democratic Republic of Congo, sparking years of unrest in the region.
Rwanda has twice sent its troops into DR Congo, saying they are needed to stop Hutu fighters, such as the FDLR, from using Congolese territory to attack Rwanda.
This led to the six-year conflict in DR Congo and the deaths of some five million people.
The FDLR are now one of the most powerful rebel forces operating in the east of the country, where they are believed to make millions of dollars a year by controlling mines rich in gold and other minerals, and extorting money from local people.
Mr Mbarushimana, who has been living in Paris, has described the force as a freedom movement, fighting "to liberate the Rwandan people from the yoke of the fascist regime" of the governing Rwandan Patriotic Front (RPF).