President Barack Obama's administration is trying to open channels of communication with Iran regarding the war on ISIS. Amid revelations that Obama sent a letter to Iran Supreme Leader Ayatollah Ali Khamenei last month pointing out the countries' shared interest in beating ISIS, a senior U.S. official and a Western diplomat tell CNN that Washington has gone through the Iraqis to communicate with Iran. The conversations do not include taking joint military action against ISIS targets, the sources said, but are seen as necessary to avert conflict in U.S. and Iranian operations. Senior White House adviser Dan Pfeiffer wouldn't address specific outreach efforts in an interview with CNN's Wolf Blitzer, but said: "We work very closely with the Iraqis and the Iraqis have a relationship with the Iranians."
@highlight
Sources say Obama noted Iran, U.S. both interested in defeating ISIS
@highlight
United States is deep into talks with Iran about its nuclear capabilities
@highlight
Sources say that's the main block to the countries cooperating on ISIS
Obama has made at least two other overtures to the @placeholder since taking office in 2009.