STRASBOURG: The president of the European Commission, Jean-Claude Juncker, sought on Wednesday to rally support for the European Union, saying the bloc battered by the UK Brexit referendum was not about to break up despite its existential crisis.

In setting out the Commission's plans for the first time since the UK voted to exit the EU on June 23, Juncker highlighted the British referendum as a warning that the EU faces a battle for survival against nationalism in Europe.

"The European Union doesn't have enough union," Juncker told the European Parliament in Strasbourg. "There are splits out there and often fragmentation exists ... That is leaving scope for galloping populism," he said.

But he underlined he believed the world's biggest trade bloc was still an important force. "The EU as such is not at risk," he said.

Proof of that, Juncker said, was the success of a new European investment fund that the former Luxembourg premier proposed to double to 630 billion euros ($707 billion) by 2022 to help with a sharp fall in spending since the global financial crisis, helping projects from airports to broadband networks.

"Our European investment fund will provide a total of at least 500 billion of investment by 2020, and will work to reach 630 billion by 2022," he said. "If with member states contribute we can get there even faster."

Juncker also wanted to extend the fund to the private sector in Africa to help curb emigration to Europe, starting with a pot of 44 million euros that could also be doubled later on.

An Africa fund was part of Juncker's efforts to stress a more positive agenda, particularly over the migration crisis that has deeply divided the European Union. He also had veiled criticism of eastern European countries unwilling to take in refugees from North Africa and the Middle East.

"Solidarity must come from the heart. It cannot be forced," Juncker said.

But the Juncker address offered few clues to the negotiations with London that the EU insists cannot start until Prime Minister Theresa May formally sets starts a two-year countdown to British departure. Juncker urged that to be done quickly. A summit of the 27 EU leaders in Bratislava on Friday is also unlikely to shed much light on the Brexit issue.

Instead, Juncker warned that the remaining EU governments should narrow their differences on addressing many problems facing their economies and societies, although he had no plans for "United States of Europe." Aides say he believes the divisions are as great as he has known them in three decades at the heart of EU politics.

"What are we instilling in terms of values in our children. Is this a union that has forgotten its past, has forgotten its past? Our children deserve better," Juncker said, speaking of his father, who fought in World War Two.