Prime Minister David Cameron told ITV News Europe Editor James Mates the EU leaders discussed how they could encourage transition in Syria "at the top" - through the United Nations - and help and advise the Syrian opposition forces.
Mr Cameron said they had not discussed the possibility of military intervention during the summit:
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The 36-year-old has not been seen or heard from since Thursday evening.
Sophie Neville, cast as Titty as a young child in the 1974 classic Swallows and Amazons, is advising its modern-day adaptation.
At least two people are feared dead in the attack which is the latest on medical facilities in the war-torn country.