Members of the Iranian army march in a parade marking National Army Day in front of the mausoleum of the late revolutionary founder Ayatollah Khomeini in Tehran, Iran, April 18, 2014. On February 22, 2015, Iran announced the official end of a special mission defending its western borders against advancing Islamic State forces in Iraq. Photo by Maryam Rahmanian/UPI | License Photo

TEHRAN, Feb. 22 (UPI) -- Months after threatening to invade Iraqi territory, Iran announced Sunday the end of a special mission safeguarding its western border against Islamic State militants.

Brigadier General Kiumars Heidari, deputy commander for Iranian ground forces, told the Islamic Republic News Agency that the mission placing army units on the western border with Iraq had ended 45 days after a "red-line warning" was issued to IS forces to stay 40 kilometers, or 24 miles, from Iran's border.


In September army commander Brigadier General Ahmad Reza Pourdastan said that Iran would attack "deep into Iraqi territory" if IS forces came too close.

"In that time, we made them understand that if they crossed that red line, they would face crushing response by the Iranian Armed Forces," Pourdastan recently told IRNA. "We noticed that the Takfiri terrorists had received our message and left the area immediately."

Heidari said that ground forces -- specifically artillery units -- were still in the vicinity of Iran's western border but were no longer assigned to the particular task of defending against IS. Pourdastan stressed that this could change, however, and that Iran's military was prepared to safeguard the border at any moment.

Iranian forces have in the past indirectly engaged IS militants. A general with Iran's Revolutionary Guards was killed by an IS sniper late last year as he trained Iraqi troops and Shia militia in Samarra, Iraq.

An attack on Iran's abandoned embassy in Tripoli, Libya, was claimed by an IS affiliate in the country on the same day as Iran's announcement.