"NATO will not tolerate any threats to a safe and secure environment in Kosovo and will react swiftly and resolutely," defense ministers said in a final communique after a two-day meeting in Brussels.
Ethnic Albanian politicians have warned that putting off a U.N. plan that would grant independence to the province could result in violent protests.
Kosovo, a province of 2 million people of whom 90 percent are ethnic Albanians, has been run by the U.N. since mid-1999 when a NATO air war halted a crackdown by Serb forces on Albanian secessionist rebels.
In February, U.N. police killed two rioters when they confronted thousands of ethnic Albanians who had broken through a security cordon and tried to march toward a government building in Pristina, the provincial capital. And 19 people died in a series of anti-Serb riots in March 2004 riots that displaced thousands and damaged hundreds of Serb homes and medieval churches and monasteries.
The Security Council has not set a date to vote on a resolution to endorse the recommendation of U.N. special envoy Martti Ahtisaari for independence for Kosovo under international supervision.
The United States and European Union back Kosovo's bid for independence.
But this it vehemently opposed by Serbia which is backed by Russia. Moscow contends independence would set a dangerous precedent for the world's other breakaway regions.
The issue has become one of the main irritants in relations between Moscow and Washington. It also has caused differences within the EU and NATO, because some European nations with secessionist movements of their own are worried that Kosovo's independence could encourage separatist demands.
NATO spokesman James Appathurai said the alliance backed Ahtisaari's proposal - known as Plan A - and warned that a delay could exacerbate divisions within its 26 member states.
"Nobody wants a situation in which there would be no Security Council resolution, because this would risk differences in views ... within Europe and potentially within NATO," he told journalists.
"That is why everybody wants Plan A," Appathurai said. "We need a political road that will ... ensure the unity of the European Union and NATO on this issue."