The withdrawal of Iranian forces is not up for discussion, the Syrian deputy foreign minister was quoted as saying on Wednesday, after Washington demanded they pull out of Syria's conflict.
U.S. Secretary of State Mike Pompeo has demanded Iran make sweeping changes -- from dropping its nuclear program to leaving the Syrian war -- or face severe economic sanctions.
"Whether Iranian forces or Hezbollah withdraw or stay in Syria is not up for discussion because it's the (business) of the Syrian government," Lebanon's al-Mayadeen TV cited Syrian Deputy Foreign Minister Faisal Mekdad as saying.
In Syria's seven-year conflict, Iran has provided vital support to President Bashar al-Assad's military. Its forces and the militias it backs from the region, including Lebanon's Hezbollah, helped Damascus claw back control of major cities from militants and rebels.
Russia has also deployed forces to help the Syrian state.
Pompeo said Iran must withdraw all forces under its command in Syria. Tehran dismissed the U.S. ultimatum and one senior official said it showed the United States seeks "regime change" in Iran.
Mekdad added that Damascus plans to take back every inch of the country, and the next target could be north or south after crushing insurgents in a string of enclaves around the capital.
"This is our decision and the decision of our friends," the pro-Syrian government channel cited him as saying in an interview with Russian state news agency Sputnik.
"After ending the direct terrorist danger to Damascus, the door is open to heading north or south."