By Stefan J. Bos
Prosecutors identified the man only as 26-year-old G.Sh, who is also a Belgian citizen. They said he lived with the woman, named as 25-year-old E.H., near the capital Pristina.
He allegedly asked his partner to carry out a suicide attack with a vehicle carrying explosive devices against international NATO troops in Kosovo.
Officials also said that the man planned terror acts in public places in Belgium and France.
Additionally, they were recruiting for extremist groups, officials say.
The man's attorney suggested his client is innocent, saying the prosecution has not offered any evidence to detain him.
But police said they recorded the suspect's telephone conversations with the woman, in which they allegedly discussed planning attacks. They also expect the investigation to extend to more suspects.
The arrests came after a Kosovo court jailed eight men while fining another man for plotting to attack the Israeli national soccer team in neighboring Albania in a World Cup qualifying match in 2016. "There is no place for extremism in this land," said Pristina court judge Hamdi Ibrahimi during that May sentencing hearing.
"The defendants' acts were designed to create both in Kosovo and Albania a climate of uncertainty, to let the extremist elements get in and to destabilize the country with acts of terrorism."
More trials are likely as Kosovo authorities say that at least 180 of the country’s citizens remain active in extremist groups in Syria and Iraq.
They come at a sensitive time as the European Union's rule of law mission will cease its judicial activities on June 14.
It was set up in December 2008, ten months after Kosovo unilaterally declared independence from Serbia.
Spending several hundred million euros over the decade, hundreds of judges and police officers served with the mission known as EULEX, the EU's most massive civilian operation ever.
But critics complain that the assassination of a journalist and many crimes committed during Kosovo's war for independence remain unsolved Kosovo's war in the late 1990s claimed an estimated 13,000 lives.
The NATO alliance has some 4,500 soldiers in Kosovo helping to keep a fragile peace.
Additionally, the European Union and the United Nations also have security and diplomatic missions there.