Reuters says 16 retired US-supplied Cobras will help fend off insurgents on Syrian and Iraqi borders.

Israel has given retired US-supplied Cobra combat helicopters to Jordan to help it fend off insurgent threats on its Syrian and Iraqi borders, a US official with knowledge of the deal told Reuters Thursday.

The supply of the choppers was initiated last year and has been approved by the US, which provided mechanical overhauls for the aircraft before they were transferred into Jordanian hands, free of charge.

"These choppers are for border security," the American official, who requested anonymity due to the sensitivity of the issue, told Reuters. He said about 16 Cobras were involved, though some may have been used by the Jordanians for spare parts.

Jordanian and Israeli officials declined comment, as did the Pentagon.

Jordan is gearing up for a possible invasion by Islamic terror groups, local media reported in mid-June.

According to reports, King Abdullah II, while touring border areas near Iraq and Syria on June 15, offered to arm Bedouin tribes living in those areas - on both sides of the border - to fight against Islamic State and Nusra Front, which threaten Jordan from the east and north.

Abdullah's concern has been growing in recent weeks, reports said, over the fact that after 3,000 bombing raids by the US and its allies, ISIS has not been beaten back – and seems only to get stronger.

With the organization solidifying its rule in much of Iraq and Syria - and in line with its pledge to expand its “Islamic caliphate” to the entire world, starting with the Muslim countries - Abdullah believes that Jordan is high up on ISIS's list for an attempted takeover.

Meanwhile, Jordan faces another danger from the north.

The Nusra group, a fundamentalist organization associated with Al Qaeda, controls much of the area on the other side of the Syrian border. This group, too, has expansionist plans, and the open frontier between Syria and Jordan is almost an open invitation to incursions by the group.

Abdullah stated that it was Jordan's obligation “to assist Arab tribes in Iraq and Syria,” hinting that he would rely on the tribes as a first line of defense against incursions by ISIS and Nusra.

The tribes living on both sides of the border have close ties, and Abdullah believes that they would aggressively defend their areas from invasion by the Islamist groups, reports said.