Syrian President Bashar al-Assad has denied he ordered the killing of thousands of anti-government protesters, telling a U.S. journalist he does not control the forces implementing his country's brutal crackdown.

In a rare interview that aired Wednesday, Mr. Assad told ABC News that although he is president he does not “own the country, so they are not my forces.” The Syrian leader said there is “a big difference” between having “a policy to crack down and having mistakes committed by some officials.”

Mr. Assad questioned the U.N. death toll of 4,000 since unrest erupted in March, saying most victims were government supporters. He also denied the veracity of claims that a 13-year-old boy whose death galvanized protests and inflamed world opinion was killed after being shot, burned and castrated.

U.S. State Department spokesman Mark Toner repeated the U.S. view that Mr. Assad is engaged in a brutal crackdown on a peaceful opposition movement. He said he finds it “ludicrous” that the Syrian president is “attempting to hide behind a sort of shell game and claim he does not exercise authority in his own country.”

On Tuesday, Secretary of State Hillary Clinton held a rare meeting with seven Syrian opposition leaders in Geneva as the U.S. and French ambassadors returned to Damascus after an extended absence.

Clinton told senior members of the Syrian National Council – all exiles in Europe – that a democratic transition involves more than removing Mr. Assad's regime. She said “it means setting the country on the path of the rule of law and protecting the universal rights of all citizens.”

The top U.S. diplomat said the opposition understands that Syrian minorities needed to be reassured they would be better off under a government of tolerance and freedom.

Mr. Assad is a member of the minority Shi'ite Alawite sect, while most Syrians are Sunni Muslims. The country is also home to a number of other religious and ethnic minorities, including Christians and Kurds.

Meanwhile, violence in Syria escalated sharply Monday, with activists reporting more than 50 deaths as the central city of Homs was convulsed by a series of kidnappings, random shootings and revenge killings. Thirty-four of the dead were shot execution style, their bodies dumped in the streets.

The London-based Syrian Observatory for Human Rights called it “one of the deadliest days since the start of the Syrian Revolution.”