Juncker, who is also prime minister and finance minister of Luxembourg, said that the euro had risen "gradually" rather than suddenly.
"There is no reason to panic," he said.
He was speaking in Berlin prior to a meeting of the Ecofin meeting of European Union finance ministers.
"We need greater transparency on hedge funds. We are working on this," he said.
- A route to economic growth – The Belt and Road Initiative 2018 survey
- Policymakers should act now to prevent next crisis – IMF panellists
- Dudley backs floor-based system for setting monetary policy
- The Bank of Italy’s approach to risk-based budgeting
- Asian Infrastructure Investment Bank – Raising expectations