The United States challenged Syria on Wednesday to accede to a request by Lebanon and open an embassy in Beirut.
"They need to establish good, transparent neighborly relations not only with Iraq, but with all the rest of the countries in the region," State Department spokesman Sean McCormack said.
But he said the reason Syria has refused to oblige the Lebanese "really gets to the heart of the matter - that the Syrian government has not given up its aspirations to control Lebanon, whether that's overtly or covertly."
The tough rhetoric followed a trip to Syria and Lebanon by Sens. John Kerry and Christopher Dodd designed to ease tensions in the region, and one to Damascus last week by Sen. Bill Nelson.