The move came after the Syrian embassy announced suspension of consular services.
"In consideration of the atrocities the Assad regime has committed" against the Syrian people, "we have determined it is unacceptable for individuals appointed by that regime to conduct diplomatic or consular operations in the United States," the Special US Envoy for Syria Daniel Rubinstein said.
"Consequently, the United States notified the Syrian government today that it must immediately suspend operations of its Embassy in Washington DC and its honorary consulates in Troy, Michigan, and Houston, Texas," he said.
The envoy said "Despite the differences between our governments, the US continues to maintain diplomatic relations with the state of Syria as an expression of its longstanding ties with the Syrian people, an interest that will endure long after Bashar al-Assad leaves power".
"The United States will continue to assist those seeking change in Syria, to help end the slaughter, and to resolve the crisis through negotiations - for the benefit of the Syrian people," he said.