BEIRUT, Lebanon — As fierce fighting continued across Syria on Sunday, the country’s foreign minister, on a visit to Iran, blamed Saudi Arabia, Qatar and Turkey for the escalation of violence and vowed that his government would rout the rebels fighting the army in Aleppo.

“Their plots will fail,” said the minister, Walid al-Moallem. But, he added, that would not stop the “campaign on the international stage against Syria.”

Mr. Moallem made his remarks as the Syrian government continued to pound neighborhoods in Aleppo, Syria’s largest city, which has become the latest front in the bloody conflict. In recent days, as opposition fighters have moved to gain control of Aleppo’s neighborhoods, the government has sent armored columns, troops and helicopters to meet them — preparing, residents fear, to move into the city.