[President of the European Commission Jean-Claude Juncker is expected to unveil plans to boost prosperity and security in his State of the Union speech]© POOL/AFP/File Etienne Oliveau Strasbourg (France) (AFP) - European Commission head Jean-Claude Juncker will urge the EU to stick together after the trauma of Britain's vote to leave when he delivers a keenly anticipated State of the Union speech on Wednesday. Two days before the 27 European Union leaders meet in Bratislava without Britain, Juncker is expected to unveil plans to boost prosperity and security in an increasingly uncertain and dangerous world. His annual speech to the European Parliament in Strasbourg will also be closely watched after reports about the 61-year-old's health, and criticism about his role in the failure to stop Britain crashing out of the EU. Juncker's spokesman Margaritis Schinas said it was a "big European week" and added that the Commission chief would be "working for the unity of our member states, delivering for citizens." EU leaders are trying to steady the ship after Britain's shock June 23 vote to become the first country to leave the union, already buffeted by a perfect storm of globalisation, terrorism and the biggest refugee crisis since World War II. At the Bratislava summit they will start work on a roadmap for the future, including a joint plan by France and Germany for a "more active" European defence policy now that an always reluctant Britain is on the way out. - 'A moment to unite' - In a summit invitation letter published late Tuesday, EU President Donald Tusk said it would be a "fatal error" for the EU to ignore the lessons of Brexit, adding that Bratislava should be a "turning point' for securing the EU's borders. The speech by Juncker, the head of the European Union's powerful executive arm, will set the scene for Friday's summit with a "positive agenda for the coming 12 months – backed by concrete proposals," a Commission spokeswoman said. His key theme in Strasbourg will be keeping the remaining 27 member states together in the face of multiple challenges, and the means to build unity, European sources said. "This is not a moment to divide, it's a moment to unite," one source told AFP on condition of anonymity. The difficulties of keeping Europe united were underscored however on Tuesday when Luxembourg's foreign minister said Hungary should be suspended from the EU for violating democratic values and treating refugees like "animals". Meanwhile Juncker will focus on the digital economy, his signature investment plan and measures to help young people hit by the eurozone debt crisis, with youth unemployment still at record levels in Greece and southern Europe. Juncker is also set to discuss boosting cooperation with African countries to stem the migration crisis -- which has seen more than one million refugees and migrants flee to Europe from Syria and elsewhere -- and security in the wake of Islamic State attacks. - 'What citizens want' - The European Commission's recent decision to hit US tech giant Apple with a 13-billion-euro bill for back taxes in Ireland is also expected to feature, a decision many European lawmakers welcomed. "That is the kind of Europe that citizens want," said the head of the parliament's socialist group, Gianni Pittella about the Apple verdict. But Juncker's performance in front of more than 750 MEPs will also be closely scrutinised amid speculation about his health, despite strong denials by him and his spokespeople. Reports about growing opposition to Juncker from Germany and some eastern European countries have also led to talk about his position as head of what he sees as a "political" Commission instead of just a bureaucracy. A Czech minister even suggested earlier this year that Juncker should quit over Brexit but he has said the vote was an issue for the British people and that he did his best to keep them in.