Gates' visit marked the first time a U.S. Cabinet member has been to Kosovo since the country declared its independence in February. And it underscored the escalating tensions between NATO allies and Moscow as former Soviet bloc nations increasingly look to the West.
Gates, who will meet with the country's top leaders during a daylong stop, said his main goal was to meet with U.S. troops serving in Kosovo as part of a coalition of more than 30 nations, with a force of roughly 15,000.
There currently are about 1,600 U.S. troops in Kosovo. The last time a U.S. defense secretary was here was Donald H. Rumsfeld in June 2001. At that time, U.S. and NATO peacekeepers were struggling to halt the flow of weapons across the border into Macedonia.
Soldiers watched for mule trains hauling the supplies across the border to aid Ethnic Albanian rebels who were fighting the Macedonian government.
This time the struggle is more political. Gates' visit coincides with an expected legal battle over Kosovo's independence, as Serbia seeks a ruling from the International Court of Justice on the fledgling nation's legality.
The U.S. and most European Union nations have recognized Kosovo's independence, but others worry that such acceptance could energize other separatist movements such as those in Spain's Basque region.
Serbia considers Kosovo its religious and historic heartland and, along with Russia, has rejected the declaration.
The conflict is one of several that have led to growing discord between Russia and the U.S. and many NATO allies. But relations plunged in August when Russia invaded its smaller neighbor, the former Soviet republic of Georgia.
Gates has urged calm in the wake of the brief Russia-Georgia war that enraged Europe and the U.S. A Russia expert who formerly led the CIA, Gates has said Moscow is not seeking global dominance, but instead is looking to "exorcise past humiliations" and recapture its glory days.
As he headed for Kosovo, Gates said it is not productive to make broad pronouncements that various ties with Russia be severed.
Instead, he said, "we have to figure out the right path in terms of the reality that we have to do business with Russia on important issues, but at the same time, to convey the message that it can't be business as usual after what happened in Georgia."