Iran has sent over 1,000 military advisers to fight ISIS in Iraq

Iran has sent more than 1,000 military advisers to Iraq since June to combat the Islamic State in Iraq and Syria (ISIS).

Tehran has also spent more than $1 billion on military aid to the country, The Washington Post reported Sunday.

The report highlights the fact that U.S. and Iranian forces are stationed in the same country fighting the same enemy, despite longstand hostilities.

Iran is reportedly backing Shiite militias to combat ISIS. They have also sent elite Quds Force units into the country to participate in operations against the terrorist group.

They have also backed Kurdish forces who have been strong partners with the United States. In August, Iran provided weapons to the Kurds as they began to take a larger part in the conflict.

The Huffington Post reported earlier this month that U.S. officials were aware that Iran was bombing ISIS targets in the same airspace as the U.S.-backed anti-ISIS coalition.

With Iraq badly outmatched by ISIS over the summer, Iran was reportedly quick to respond while the U.S. debated how to contribute to the fight. The Obama administration eventually started the airstrike campaign and sent advisers and aid to Iraq.

The conflict with ISIS has unfolded alongside talks between the U.S. and Iran over the latter’s nuclear program. The administration is hoping that they will be able to reach a deal over the program’s enrichment capabilities by a spring deadline, but Republicans say that that want to consider new sanctions against Iran in early 2015.

Sen. Lindsey Graham (R-S.C.) on Saturday said the Senate will move on new sanctions against Iran in January.