2009 G20 London summit a force for good in the medium term." Leaders of the member countries began to prepare for the London Summit months before the effective date, notably with two official meetings dedicated to that preparation, one held in Berlin, Germany, on 22 February 2009 for European leaders, and another in Horsham, Sussex, United Kingdom, on 14 March 2009 for Finance Ministers. Leaders of the four European Union member countries of the G20, the United Kingdom, Germany, France and Italy along with the two largest European non-members, Spain and the Netherlands, met in Berlin on 22 February 2009 to prepare for the
2018 G20 Buenos Aires summit with improvised explosive devices. After those events, the United Kingdom government lowered its terrorism alert for Buenos Aires from "very likely" to "likely". 2018 G20 Buenos Aires summit "" The 2018 G20 Buenos Aires summit, was the thirteenth meeting of Group of Twenty (G20), which was held on 30 November and 1 December 2018 in the city of Buenos Aires, Argentina. It was the first G20 summit to be hosted in South America. President Mauricio Macri of Argentina assumed the one-year G20 presidency on 30 November 2017, during an official ceremony at the Kirchner Cultural Centre in Buenos Aires. President