Serbia's ambassador to NATO committed suicide by jumping from a multi-storey car park at Brussels airport on Tuesday, local media reported.
Serbia's foreign ministry said in a statement Wednesday that Branislav Milinkovic had "died tragically" in the Belgian capital but gave no further details.
NATO expressed regret at the news.
NATO head Anders Fogh Rasmussen "is deeply saddened by the tragic death of the Serbian ambassador. Mr Milinkovich was a highly respected representative of his country and will be missed," an alliance spokeswoman said.
Milinkovic "committed suicide by jumping from a multistorey car park at the international airport in Brussels in the presence of Serbian deputy foreign minister Zoran Vujic," Serbia's Blic newspaper reported on its website, quoting diplomatic sources.
It gave no motive for the apparent suicide.
A diplomatic source in Brussels said Milinkovich had gone to the car park used for VIPs to meet a senior Serb official on Tuesday.
As the delegation arrived, he apparently moved away from them and then jumped over the car park wall, the source said.
Serb journalists said Milinkovich had appeared normal during the day, talking and chatting with them as they covered a NATO foreign ministers meeting.
Brussels airport spokesman Jan Vad der Cruysse confirmed that a man had jumped from the car park and that rescue services had been unable to save his life.
Serbia is not a full member of the NATO military alliance but belongs to its "Partnership for Peace" programme which provides for a range of cooperation on defence and security issues.
Milinkovic, 52-year-old career diplomat, was ambassador to the Organisation for Security and Cooperation in Europe before being appointed Serbia's NATO envoy in 2010.
NATO forces help to keep the peace between Kosovo and Serbia which refuses to recognise Pristina's 2008 declaration of independence.
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