Talks on Britain leaving the European Union began Monday with both sides saying they will focus first on an orderly withdrawal.
British media named the suspect as Darren Osborne, 47-year-old father of four who was living in Cardiff, Wales.
Moscow has only once before suspended the hotline, which was established in October 2015 to prevent conflict between the different forces operating in Syrian airspace.
Goldman Sachs is scouting for office space in Frankfurt that could serve as its new trading hub inside the European Union after Brexit.
The European Union committed 50 million euros to help the countries of West Africa's Sahel region set up a multinational force to combat Islamist militant groups.