Bernard Kouchner, Kosovo's top U.N. official, and Lt. Gen. Juan Ortuno, commander of 47,000 NATO-led peacekeepers, spoke on the first anniversary of NATO's arrival.
Citing examples of progress, Ortuno said that murders, at 50 a week a year ago, are now down to six a week.
The peacekeepers entered June 12, 1999 at the end of 78 days of NATO bombing of Yugoslavia after President Slobodan Milosevic agreed to end his crackdown on ethnic Albanians and pull his troops out of the province.
"For the U.N., the Kosovo mission is a success," Kouchner said. Still, he added, "we need a significant amount of years, and we need a lot of patience ... to set up a society based on coexistence and tolerance."
Among the successes he listed were the return of 800,000 refugees; the disbanding of the Kosovo Liberation Army that fought Milosevic's troops; improvements in the economy; and implementation of a government open to all ethnic groups even if Serbs are presently staying away.
Agricultural production in Kosovo is also progressing. The U.N. Food and Agriculture Organization in Rome said Monday it is planning to scale down its emergency assistance to Kosovo. The number of families receiving aid will decrease from 70,000 to 40,000 by the end of the year because of the positive results so far.
Some 197,600 acres have been planted with wheat, which is only 10-12 percent less than a normal year, said agency spokesman Daniele Donati.
On the negative side, Kouchner spoke of "the lack of human rights, the lack of security" - an allusion to the recent rash of attacks on Serbs, which has driven a further wedge between them and majority Albanians.
Serbs have been targeted by revenge-minded Albanians since the pullout of Milosevic's troops, leading tens of thousands to flee the province and leaving only an estimated 100,000 behind.
Two Albanians were killed and a third was wounded near Kosovska Mitrovica, 20 miles north of the provincial capital of Pristina on Sunday, NATO officials said. Residents said a survivor told them the killers were Serbs, but NATO could not confirm that.
Also addressing ethnic violence, Ortuno condemned those "who want to perpetrate a climate of hatred and violence."
NATO "will remain in Kosovo for as long as necessary" to eliminate such a climate, he said.
In an indication of the hostilities that linger in the province, 200 Serbs blocked a road linking the divided city of Kosovska Mitrovica with Zvecan to the northwest, demanding that NATO-led peacekeepers provide escorts for their trips to Serb enclaves in central Kosovo.
The protesting Serbs parked cars on the road and said they would keep it blocked until escort were provided.