Zebari met Wednesday in Tehran with his Iranian counterpart, Javad Zarif, dismissing claims that both sides had reached a military sales agreement.
"No agreement has been made for purchasing weapons from Iran," he was quoted by the semiofficial Fars News Agency as saying.
U.S. State Department spokeswoman Jen Psaki said during a Tuesday press conference the Iraqi Ministry of Defense issued a statement denying there were any contracts signed with Iran. She said Monday if such a deal was in the works, it would likely violate existing sanctions on Iran.
Iraq is working to restore security to western Anbar province, where elements of al-Qaida are re-emerging.
U.S. officials have said al-Qaida is exploiting political divisions between Sunni and Shiite leaders as Iraq prepares for national elections in April.
The State Department said the U.S. military has provided equipment to its Iraqi counterparts as part of a foreign military sales program to help with national security.
U.S. military forces twice battled insurgents in Anbar province before combat operations ended in 2011.