LONDON — Borrowing costs for Spain and Italy eased once again on Monday as officials in the region continued voicing their commitment to supporting the euro currency union.

The German finance minister, Wolfgang Schäuble, and the United States Treasury secretary, Timothy F. Geithner, issued a joint statement expressing confidence in euro zone members’ efforts to revamp their economies after meeting on the North Sea island of Sylt.

And Jean-Claude Juncker, Luxembourg’s prime minister and the head of the Eurogroup of 17 euro zone finance ministers, added his support in comments published Monday in Le Figaro in France and Süddeutsche Zeitung in Germany.

“The euro zone is at a point where it must prove, with all its means, its determination to guarantee stability,” Mr. Juncker said, adding that “no one should doubt the collective will of the 17 countries.”