Israel has gifted Jordan with 16 military gunships to help them fend off attacks from the Islamic State terror group and other jihadi outfits. The Cobra helicopters “are for border security,” an unnamed U.S. official told Reuters.

The helicopters were initially sent to Israel via Bell Helicopters, a U.S. defense contractor based in Texas. They were decommissioned in 2005 and 2013 and replaced with Apache helicopters, the Times of Israel reported on Friday.

According to officials with knowledge of the border situation, Jordanian King Abdullah II is said to be concerned with the security situation on his borders, and has offered to arm Bedouin tribes in the north to defend against ISIS and other jihadist groups.

Abdullah II said this week that Jordan has the duty “to assist Arab tribes in Iraq and Syria.”

Following the brutal killing of a Jordanian pilot by ISIS militants earlier this year, Abdullah pledged to respond with force, “because this terrorist organization is not only fighting us, but also fighting Islam and its pure values.”

Israeli and Jordanian officials have not commented on the helicopter transfer. The two countries remain publicly at odds over numerous issues, but continue to cooperate behind the scenes on mutual interests.

It appears as if the the Israelis have not requested anything in exchange for the helicopters.

The Cobra gunships are part of a growing Jordanian Air Force that includes F-16 fighter jets previously acquired from Europe.