NATO can be a positive force when it takes military action with a UN mandate, said Kees Homan, a researcher at the Netherlands Institute of International Relations.

"NATO can be a fairly positive factor in the security environment when it bases its actions on (UN) Security Council resolutions. That is very important," Homan told Xinhua in an interview on Tuesday.

The UN has no military capabilities. NATO can play an important role in conflicts when the UN cannot cope with them, he said.

But he expressed the hope that when NATO operates, it will always act on Security Council resolutions. "NATO is an international organization which is capable, based on resolutions of the Security Council, to take substantial military actions," he said.

Homan, who retired as a major general of the Dutch military, expressed concern over the divisions among NATO member states on its operations.

"The main pillars of NATO should be, as shown during the Cold War, solidarity and sharing of risks. When I look at Afghanistan at this moment, I can't say that there is solidarity. And there is no willingness of NATO member states to share risks."

Only a few NATO countries are willing to take risks in fighting the Taliban-led insurgents in southern Afghanistan, where exists a disturbing situation, he said.

Homan said there would be more such scenarios for NATO in the future. There might be political agreement on military action. But at the end there will only be "coalitions of the willing and the able," he said. "NATO has its assets. But only those member states which are interested will contribute their military means."

NATO also needs to renew its strategic concept given the big changes in the security environment since the publication of its current Strategic Concept in 1999.

The NATO summit to be held in Strasbourg of France and Kehl of Germany on April 3 and 4 is expected to launch the process of updating NATO's strategic concept.

NATO Secretary General Jaap de Hoop Scheffer said cyber-warfare, energy security, climate change would be added to the new document as NATO's tasks.

Homan said relations between NATO and the European Union (EU) should be a major element of the strategic concept.

"Good cooperation and good relationship between NATO and the European Union (are important) because in a new security environment, to solve those security problems we are confronted with, we need this comprehensive approach."