Senate Republicans want President Obama to send military advisers to Jordan to help the country develop a defense against the Islamic militant group now fighting to take over Iraq and other areas of the Middle East.

In a letter signed by 18 GOP lawmakers, including Senate Minority Leader Mitch McConnell, R-Ky., and Sen. John McCain, R-Ariz., Republicans told Obama he needs to develop a strategy for dealing with Islamic State of Iraq and the Levant, which now occupies parts of Syria and Iraq and is threatening the stability of the whole region, including American allies such as Jordan.

“Your administration has not developed a coherent strategy for defending the United States and our allies from either ISIL or the Al Nusrah [an affiliated Al-Qaeda group] front,” the senators said in the letter. “We are asking you to take urgent action and develop such a plan.”

The letter calls on Obama to send “an assessment team” to Jordan to help the country defend itself against the militant groups.

“We view King Abdullah II as an invaluable ally, and view the defense of Jordan as critical to the national security interests of the U.S. — and Israel.”

Obama last month announced he would send up to 300 “military advisers,” to Iraq to help advise and train the Iraqi government to defend itself against ISIL. Jordan, which borders Syria and Iraq, has been left vulnerable to the terrorist organization.