Greek and U.S. negotiators ended their 16th round of talks on the future of American military bases in the Mediterranean country with "little progress toward a new accord," a government spokesman said Friday.

The negotiators, who began the most recent round of talks Monday, are trying to reach a comprehensive defense and economic cooperation pact that would determine the future of four major U.S. military bases and 20 smaller installations on Greek soil.Greek government spokesman Sotiris Kostopoulos said the two sides "examined the preamble and various aspects of a possible agreement, but there was no notable progress."