Attendees quickly moved ahead on a subject that was expected to dominate much discussion: Kosovo, where NATO currently leads some 16,000 KFOR peacekeepers.
Ministers reportedly agreed that NATO would train a future security force for Kosovo, which declared independence from Serbia in mid-February and was due to put a new constitution into effect on June 15, despite disagreement over Kosovo's official status and security arrangements, according to dpa.
The UN Mission in Kosovo (UNMIK) is meant to transfer some powers to local authorities, with the support of a European Union police and justice mission.
But that EU mission faces delays, leaving NATO members worried they could be burdened with policing duties. So the alliance is keen for UNMIK police to stay until the EU mission is deployed.
Kosovo was just one of the issues in what was a full agenda for two days of talks, however.
"While these meetings will cover a range of subjects, everything from NATO's mission in Kosovo to European missile defense, clearly a lot of time will be spent on Afghanistan," Pentagon spokesman Geoff Morrell said ahead of the gathering.
"After the heads of state recommitted themselves to that mission [at the NATO summit] in Bucharest last April, the Brussels meetings will serve as an opportunity to get a status check on pledges for additional forces and equipment, implementation of the strategic vision statement, and how well the allies are supporting [UN special representative] Ambassador Kai Eide in his efforts to better coordinate civilian reconstruction in Afghanistan," Morrell added.
That "strategic vision" promised a "firm long-term commitment" to Afghanistan. It included a pledge to fill gaps in the NATO-led force and a target of 2010 for the creation of an Afghan army of 80,000 troops.
Now at this week's Brussels meeting, U.S. Secretary of Defense Robert Gates is expected to ask his NATO partners for help to beef up the Afghan police training effort.
Ministers are also expected to discuss Afghanistan's volatile south, where several NATO allies have taken turns at command. Britain and the Netherlands have agreed to extend their command in the south to a year from nine months, starting later this year.
Then on June 13, attention turns to Russia with ministers meeting their Russian counterpart, Anatoly Serdyukov.
They are expected to discuss Moscow's tensions with Georgia as well as U.S. plans to put parts of a missile-defense system in Central Europe.
NATO has endorsed those plans, which are strongly opposed by Russia. The meeting comes on the heels of Russia's new president, Dmitry Medvedev, saying that NATO's eastward expansion could spoil relations between Russian and the West.
On June 11, Medvedev said NATO alone could not handle Europe's security needs. He also reiterated a proposal on European security that he outlined on a visit to Germany last week.
"If our predecessors managed, under the conditions of the Cold War, to work out the Helsinki Final Act as the legal basis of the European system, which by the way has stood the test of time despite everything, why shouldn't we go further today and conclude a legally binding treaty on European security, which would include institutions already existing in the Euro-Atlantic region?" Medvedev asked.
NATO ministers were due on June 13 to meet Ukraine's defense minister, Yuriy Yekhanurov. At its April summit, the alliance stopped short of putting Ukraine and Georgia on immediate paths to membership.
But NATO said both would join one day and that their progress would be reviewed in December.
NATO officials said the June 13 talks would be held "against the background of the intensive engagement process launched at Bucharest."