"The presence of the US ambassador in Hama without previous permission is obvious proof of the implication of the United States in the ongoing events, and of their attempts to increase (tensions), which damage Syria's security and stability," the foreign ministry in Damascus said in a statement on Thursday.
"Syria warns against such irresponsible behaviour and stresses its determination to continue to take all measures that will bring back calm and stability to the country," the ministry added.
Last Friday, an anti-regime rally brought out half a million people in Hama, according to pro-democracy activists. The security services did not intervene and Assad fired the city's governor the next day.
In Washington State Department spokeswoman Victoria Nuland said earlier that Ford was "interested in seeing the activity tomorrow", referring to the latest in a series of planned protests after Friday prayers.
A senior US official, who spoke on condition of anonymity, said Ford was in the city "to make contact" with opposition leaders.
"We need to know who these guys are, we need to know what they aspire to in terms of political process and a different future for their country. We need to make contact and that's what he's there to do," the official said.
Hundreds of residents have fled Hama in recent hours, fearing a crackdown from the army on the eve of new demonstrations there and across the country voicing opposition to any dialogue with the Assad regime.
Damascus: Syria has accused the United States of "interfering" in the protests rocking the Middle East country for the last four months, after US ambassador Robert Ford visited the rebel city of Hama.
First Published: Friday, July 08, 2011, 10:55