Germany's Der Spiegel magazine Sunday said a classified report by German intelligence revealed the agreement between Tehran and Damascus in November 2012 to allow Syria to station its fighter jets on Iranian soil and gain access to the aircraft when needed.
The report noted the agreement was in addition to the Iranian Revolutionary Guards units Tehran has sent to assist the Syrian regime to fight the Syrian rebels.
Spiegel Online International published excerpts of an interview with Syrian leader President Bashar Assad, which comes out in full Monday.
In the interview, Assad insists his regime "did not use any chemical weapons." He called accusations that he is responsible for chemical weapons attacks on civilians a "misstatement," and said "so is the picture you paint of me as a man who kills his own people."
Assad insisted the chemical weapons experts sent to examine the suspected chemical weapons sites will be free to move around the country and will receive all data from the government.
The Syrian leader also admitted he has also made mistakes, but does not fear for his well-being.