ROME (Reuters) - Italian Prime Minister Matteo Renzi on Friday said he backed giving Greece more time to pay its debts in exchange for commitments to make structural reforms, as Athens seeks euro zone approval to extend a loan program. Germany has called for "significant improvements" to Greek reform commitments before signing off on an extension on loan payments. "All of us (euro zone countries) must back an agreement, and I believe that the principle of doing reforms in exchange for more time is just and correct," Renzi said following a meeting of his government in Rome. (Reporting by Steve Scherer and Giuseppe Fonte)