(Adds comment on military ties)
BRUSSELS, April 5 (Reuters) - NATO Secretary-General Jens Stoltenberg said on Wednesday Ukraine's future membership of the alliance had to be based on the country being independent and democratic, which is now challenged by Russia's invasion.
Stoltenberg told a media briefing after a meeting of NATO foreign ministers in Brussels that Ukrainian forces should have the highest possible level of interoperability with the alliance when the war ended.
