France, Germany sign friendship treaty.

The leaders of France and Germany signed a new treaty on Tuesday to update their 1963 post-war reconciliation accord, aiming to reinvigorate the European Union's main axis as growing euro-sceptic nationalism tests the bloc's cohesion.

At a ceremony in the German border city of Aachen, a historic symbol of European concord, German Chancellor Angela Merkel and French President Emmanuel Macron sought to show they can provide fresh leadership for the troubled EU project.

But some analysts doubt that France and Germany can still lead an EU that has grown to 28 members with diverse and often conflicting interests and priorities.

The two leaders want the 16-page Aachen Treaty, negotiated over the past year to update the 1963 Elysee Treaty, to give an impulse to European unity that has been strained by Brexit, immigration and the euro zone crisis.

'We are doing this because we live in special times and because in these times we need resolute, distinct, clear, forward-looking answers,' said Merkel, noting Aachen was home to Charlemagne, whom she dubbed 'the father of Europe'.

Macron added: 'At a time when Europe is threatened by nationalism, which is growing from within... Germany and France must assume their responsibility and show the way forward.'

But the treaty is short on detail and does little to push forward euro zone economic reform, though it commits Berlin and Paris to closer foreign policy and defence ties.

The head of Germany's BDI industry association, Joachim Lang, said: 'Concrete steps must follow.'

Sabine von Oppeln, expert on Franco-German ties at Berlin's Free University, said of the slow progress on euro zone reform: 'The German side is not responding to Macron's ideas, which are of course also driven by (French) national interests.'

'This could be an opportunity for a real renewal of cooperation but I fear the chance...