The visit last week aimed to discuss efforts towards stability, security and strengthening democratic institutions in southeastern Europe.
"The organisation will keep supporting the reform process going on in all these countries, which brings them closer to the accession standards defined by the European Union," Rau said.
"Our ongoing cooperation has brought about some effects now, so on each of my visits there I met with gratitude,” he added.
Michał Owczarek has the story.
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