Delegates will discuss a controversial plan for a new European Union force that could shore up borders without the host country's consent.
Wealthy or not, exit backers are swimming against a tide of business leaders urging the country to stay in, including top executives.
While European countries continue to weigh up their migrant policy, hundreds of thousands of refugees continue to flee war and poverty.
European countries are turning on one another as growing border chaos tests the limits of diplomacy.
The current confrontation will shape resistance to austerity - and the future of the whole of Europe.
European leaders wait for signs that Prime Minister Alexis Tsipras is ready to compromise as Greece fails to make its IMF payment.
Six large energy companies have asked the United Nations for help in setting up a carbon pricing scheme that would include their operations.
The euro leapt, Greek bond yields fell, but nothing actually changed in another day of talks with international creditors.
The EU is considering fielding a naval force to deal with increasingly deadly Mediterranean crossings, but the plan would have to favour with the UN.
A proposal to divide up numbers between EU states in the wake of the Mediterranean crisis could pit Germany, which backs the scheme, against the UK.
EU paymaster Germany criticised the Greek proposal as "not a substantial solution" as it failed to fulfil bailout conditions.
President Vladimir Putin said Russia would rather focus on strengthening its domestic market, but if he wanted, he could invade Kiev in just two days.
A "Yes" vote to Scotland's independence will pose baffling questions for the EU, and could see Scotland clamouring to join while England leaves.
China says the EU's proposed additional sanctions on its key ally Russia will not solve the current problems in Ukraine.
Pro-Russian separatists are preparing a fresh offensive in Ukraine as EU leaders give Moscow one week to curb support for rebels or face sanctions.
Sufficient political will is all we need to get the 58-million children not in school into classrooms by the end of next year, says Andris Piebalgs.
Major EU member states vote on Sunday to elect the 751 deputies to sit in the European Parliament until 2019.
A lack of trust in the mainstream leadership is driving EU voters to look at more radical options in this week's polls.
The European Union has expressed concern after armed groups attacked Libya's Parliament in Tripoli and an air base in the east.