"I favour starting carefully and then developing the relationship between Nato and Russia," Volker Ruhe said. "In my view, we should start with three members."
The alliance plans to offer some former Soviet bloc countries membership at an alliance summit meeting in Madrid on 8-9 July. Poland, the Czech Republic and Hungary are the most likely candidates. But some countries have plumped for other candidates. Italy has backed Slovenia and France has called for Romania to be invited.
Mr Ruhe's comments made it plain that Germany opposes widening the first group, although he said the allies have not made a final decision. Mr Ruhe added: "There must also be a clear signal that the process will continue."
There is still debate within Nato over whether enlargement will continue to include a second wave of countries.
President Jacques Chirac said yesterday that all European countries had a right to join the Atlantic alliance. Mr Chirac's office said he made the comment in a meeting with visiting Slovakian Prime Minister, Vladimir Meciar, whose country is not expected to be in the first group of countries invited to join the alliance.
There is particular concern amongst the Baltic states, Latvia, Lithuania, and Estonia, that they will not be included in the first wave of expansion. In Brussels, on Wednesday, Lithuania's Foreign Minister, Algirdas Saudargas, said at least one of the three should be included.
"In order to make the enlargement process a success, it is important that at least one Baltic country should be invited to join the alliance with the first group," Mr Saudargas told a meeting of Nato ambassadors and aspirant members. "We want to be part of the alliance, because both common sense and the success of the alliance members suggest that the best, the most effective, and the least expensive way of building and developing a national defence system is through participation in collective defence arrangements."
In Helsinki yesterday, about 30 Lithuanian students gathered across the street from President Bill Clinton's hotel to press their demand for their country's admission to Nato. The students, chanting "We will be in Nato," to the rhythm of Queen's "We Will Rock You," earlier stood outside Finlandia Hall, one of the press centres set up for the meeting of Mr Clinton and Russia's President Boris Yeltsin.
The students distributed flyers appealing to Mr Clinton to push for Nato membership for Lithuania, because "our security and enhanced stability are not a threat to anybody, neither East nor West".