The White House on Wednesday warned Syria against intervening in Iraq, amid reports Damascus had launched cross-border military strikes on an Islamist group controlling large areas of both countries.
Press secretary Josh Earnest said the U.S. had “no reason to dispute” reports of Syrian strikes on Iraqi territory against the Islamic State in Iraq and Syria (ISIS or ISIL), a militant Sunni terrorist group.
"The solution to the threat confronting Iraq is not the intervention of the Assad regime," Earnest said.
"In fact, it's the Assad regime and the terrible violence that they perpetrated against their own people that allowed ISIL to thrive in the first place," he continued. "The solution to Iraq's security challenge does not involve militias or the murderous Assad regime but the strengthening of the Iraqi security forces to combat threats."
According to multiple reports, Syrian warplanes killed at least 50 people and injured scores more in an attack on Sunni militants near the border crossing of al Qaim.
The growing insurgency in Iraq has created curious bedfellows — and a difficult balancing act for the United States.
ISIS, which has swept through Iraq's Sunni regions, grew out of a Syrian insurgency mounted against Assad’s regime.
The militants have now seized cities, oil facilities and military bases from the control of the Shiite-majority, U.S.-backed Iraqi government in Baghdad.
The U.S. is deploying 300 military advisers to help Baghdad repel the threat.
The advance of Sunni insurgents also sparked alarm among fellow Shiite leaders in Iran, with Tehran offering military support.
Earnest said Iraq's sovereignty "must be respected" by outside actors.
"It's important that no one lose sight of the way that this situation can be resolved, that an over-reliance on military tactics may address some of the symptoms but will not get at the root cause of this problem," he said.
"What the United States has been focused on is looking for ways that we can support Iraq's political leadership as they pursue an inclusive governing agenda,” he added. “That ultimately is the way that this problem gets solved."
Earnest said that despite dovetailing interests, the White House would "certainly not" communicate with the Syrian regime about the situation in Iraq.
Last week, U.S. and Iranian diplomats discussed the crisis on the sidelines of nuclear talks in Europe.