French government spokeswoman Valerie Pecresse described the fears over Spain's economic heath as "excessive.
"We think the government of Mariano Rajoy is carrying out a policy of courageous, necessary structural reforms, which can improve the potential growth of Spain and lead to a Spanish rebound," she said.
The rise in bond yields in Spain and Italy are also being seen as signs that the market-calming effects of a massive credit infusion by the European Central Bank are wearing off. The ECB made just over €1 trillion in emergency three-year loans to banks in two batches on Dec. 21 and Feb. 29.
The ocean of cheap credit removed fears of sudden bank failures, and eased borrowing for indebted governments as some banks used the cheap loans to buy higher-yielding government bonds. Bank officials have stressed that the measure was aimed at supporting banks — not governments — and that governments needed to use the respite to fix the eurozone's underlying debt problems.
Benoit Coeure, a member of the ECB's top executive board, underscored that message in a speech in Paris on Wednesday, saying that while ECB measures have helped avoid a credit cutoff to the economy the situation "remains fragile."
"Governments must build on the steps already taken to restore sound fiscal positions and support long term growth," he said.
David McHugh from Frankfurt, Geir Moulson from Berlin and Sylvie Corbet from Paris contributed to this report.