Brazilian President Dilma Rousseff has said Europe may have to rethink its economic austerity measures.
Ms Rousseff said austerity measures are starting to have dire social consequences, which can be seen in particular in the level of youth unemployment.
She also cautioned against countries such as Germany leaving the euro in pursuit of trade opportunities.
She suggested that such countries could face unforeseen problems, saying she preferred doing trade deals with the EU as a whole, not with individual countries.
Speaking to President Michael D Higgins, Ms Rousseff said that European leaders must do everything to preserve its currency.
Countries such as Brazil like having the euro as an alternative to the US dollar in international trade, she said.
Elsewhere, the International Monetary Fund has urged EU leaders to deepen financial ties within the eurozone.
It said this is a matter of urgency to restore confidence in the global financial system.
In its six-monthly report on the state of the world economy, the IMF said the eurozone's debt crisis was the main threat and the risks to financial stability had risen in the last six months.