WASHINGTON (Reuters) - German Foreign Minister Joschka Fischer said European members of NATO need to take a concerted stand on U.S. plans to build a defense against missiles from what it calls ``rogue states.''

Speaking at a joint news conference in Washington with Secretary of State Madeleine Albright, he said European states had different interests, so it could take time to agree.

``We are looking forward to unifying the position but the interests are not homogeneous within Europe so we will need some time for discussion,'' he said.

The defense system, known as National Missile Defense (NMD), has become a bone of contention between the United States and its European allies, who would probably be outside the defense umbrella and who fear this would divide NATO.

But European politicians have rarely spoken of differences between European states on the U.S. plans.

An arms control expert in Washington said there were nuances in how seriously European governments are concerned about NMD and what arguments they would use against it.

The United States says it needs the system to protect against missiles fired by countries now working on long-range missiles, such as Iran and North Korea.

It says it should not affect the strategic balance with Russia because the system would not be good enough to neutralize Russia's nuclear arsenal.

Fischer said he and Albright discussed the NMD dispute, both over dinner Sunday and at formal talk Monday.

``We understand on the one hand fully the concerns of the United States... but on the other hand the United States is the leading power in the world and this is a national decision with a very strong international impact,'' he said.

``I explained the concerns within our parliament and public opinion and we discussed all aspects,'' he added.

Albright noted that President Clinton has not yet decided whether to deploy such a decision and, when he decides, will take account of the effect on arms control agreements.

``I also think that it is very important for any president of the United States to do what is responsible as far as protecting one's people. But we are exactly in the process of consultations,'' she added.

Albright and Fischer also talked about the Balkans, preparations for Clinton's visit to Germany next month and a pledging conference to build a new sarcophagus for the nuclear reactor which exploded at Chernobyl in Ukraine in 1986.