(Recasts with test coming back negative) MADRID, Dec 17 (Reuters) - Spanish Prime Minister Pedro Sanchez tested negative for COVID-19 on Thursday but will quarantine until Dec. 24 after being in contact with French President Emmanuel Macron, who has contracted coronavirus, his office said. Sanchez, who earlier on Thursday suspended all public activities, will take another test before the end of his self-isolation, it added. Sanchez and Macron met on Monday in Paris. Video footage of Macron welcoming the Spanish prime minister at the Elysee Palace showed both wore masks and did not shake hands. (Reporting by Inti Landauro, Andrei Khalip Editing by Ingrid Melander)