France and Germany on Tuesday agreed to hammer out joint proposals for strengthening the crisis-battered eurozone as they marked 50 years since a treaty sealing their post-war reconciliation.

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German Chancellor Angela Merkel and French President Francois Hollande set past tensions aside to put on a show of unity in Berlin, announcing they planned to present the initiatives by May before an EU summit.

Speaking at a joint press conference in the midst of a hectic agenda of pomp and celebration marking the Elysee Treaty, inked in 1963, Merkel said the aim was the "stabilising and deepening" of the economic and monetary union.

Employment, growth, financial stability and competitiveness would be targeted in the proposals, which would be laid out before a European Council meeting in June, she said.

'Great responsibility to improve eurozone'

Describing Franco-German relations as "exceptionally close", Merkel said the two countries were aware of their "great responsibility of improving the situation in the European Union, overcoming the euro crisis and enabling economic growth."

Hollande said decisions would be taken in the coming months "to deepen the economic and monetary union."

"We are working on it. We will try to be as concrete as possible, that is to say, the most useful so that growth is strengthened," he told reporters, adding Europe's 2014-20 budget would also have to be resolved after talks collapsed in November.

"France and Germany have a share of the responsibility," he added. Both countries' cabinets held a joint session, followed by a debate in the historic Reichstag with nearly 400 French lawmakers who travelled to the German capital to meet their Bundestag counterparts.

Signed by then French president Charles de Gaulle and West German chancellor Konrad Adenauer, the Elysee accord formalized the cooperation between the former foes that has since been a building block of European unity.

But the half-century milestone comes amid strains in the Franco-German partnership and as the European Union faces testing times over the eurozone debt crisis and euroscepticism in Britain.

Differences on military matters

On military matters too, Paris and Berlin have limited cooperation, as the current crisis in Mali and Germany's non-intervention in Libya in 2011 have shown, but both leaders played down differences.

"We have once again shown clearly that we (Germany and France) are together," Merkel insisted to reporters, praising the "difficult" mission by French troops against Islamists in Mali.

And Hollande thanked Germany for its immediate "political solidarity" and material assistance.

Germany has pledged two military transport planes and humanitarian aid for Mali.

After Merkel backed the re-election of conservative former French president Nicolas Sarkozy -- whose joint euro crisis-fighting efforts earned them the nickname "Merkozy" -- last year, her rapport with the Socialist Hollande has got off to a cooler start.

They have differed on the best approach for stemming the eurozone turbulence -- with Hollande pushing for fresh spending to bolster growth versus Merkel's pro-austerity mantra.

Even if the two have pulled off compromises, Germany, which has fared far better in the crisis than many of its partners, has expressed hopes the French economy will return to robust growth.

But, relaxed and light-heartedly, both leaders stressed they got along well in response to a question by reporters, with Merkel calling it "perhaps our best-kept secret that the chemistry is right."

"We are on the same wavelength without needing any encouragement," quipped Hollande.