A newly proposed Senate bill would impose mandatory sanctions against Turkey – including banning the sale of weapons and targeting foreign individuals who perform military transactions with the country – in response to Ankara’s incursion against Kurdish forces in Syria this week.

Sens. Lindsey Graham (R-S.C.) and Chris Van Hollen (D-Md.) introduced the package Oct. 9 following reports that Turkey, a NATO member-state and U.S. partner in counterterrorism operations in the Middle East, had begun air and ground attacks against the Kurds in northern Syria following a withdrawal of less than 100 U.S. special operations from the area.

The bill prohibits the sale of U.S. defense articles, services, technology and materials to the Turkish Armed Forces, as well as ammunition sales and transfers to the services. It also includes sanctions on the U.S. assets of senior Turkish leaders, as well as foreign individuals who sell or otherwise engage in military or energy sector transactions with the country.

The proposed sanctions would increase the economic and diplomatic pressure on Turkey even as the Pentagon is in the process of reducing the nation’s participation in the F-35 Joint Strike Fighter program.

The nation officially took delivery of the Russian-made S-400 anti-aircraft weapon system earlier this year, after Defense Department officials and experts issued multiple warnings that the Lockheed Martin [LMT]-built F-35 and the S-400 are incompatible. Ankara has invested more than $1.25 billion toward the program, planned to procure 100 F-35A aircraft and was involved in multiple parts of the production process. Graham and Van Hollen’s package would define Turkey’s S-400 purchase as a significant transaction under Section 231 of The Countering America’s Adversaries Through Sanctions Act (CAATSA) and slap further sanctions on the country within 180 days of the act.

An unclassified FY ’19 NDAA report on the status of the U.S. relationship with Turkey that examined the potential impact of CAATSA for the S-400 highlighted several acquisition programs that would be affected by just those sanctions, including but not limited to: fighter aircraft including the F-35 and F-16 Fighting Falcon built by Lockheed Martin, rotorcraft such as the Boeing [BA] CH-47 Chinook and the Sikorsky-built UH-60 Black Hawk, as well as the Raytheon [RTN]-built Patriot air and missile defense system, which the State Department approved for sale to Turkey this year for $3.5 billion in an effort to move them away from the S-400.

Since December 2012, the State Department has approved over $13 billion worth of foreign military sales to Turkey, according to documents from the Defense Security Cooperation Agency (DSCA).

The sanctions would go into effect upon enactment of the bill “unless the Administration certifies to Congress – every 90 days – that Turkey is not operating unilaterally (without U.S. support east of the Euphrates and west of the Iraqi border) in Syria and has withdrawn its armed forces, including Turkish supported rebels, from areas it occupied during the operation beginning on October 09, 2019,” the bill’s language says.

Turkish forces launched an incursion into the northern area of Syria Oct. 8 as part of an offensive dubbed Operation Peace Spring against Islamic State and Kurdish forces that Ankara deems to be a threat to its national security.

The United States has allied with the Kurdish-led Syrian Democratic Forces (SDF) and has relied upon those troops for ground support while combating the Islamic State (ISIS) since 2015. Turkey identifies the SDF military leaders – the People’s Protection Units, or YPG – as a terrorist organization.

The Trump administration issued a statement Oct. 6 that while Turkey would begin “its long-planned operation” into northern Syria, “the United States Armed Forces will not support or be involved in the operation, and United States forces, having defeated the ISIS territorial ‘Caliphate,’ will no longer be in the immediate area.”

Graham, a former member of the Senate Armed Services Committee who frequently allies himself with Trump but has broken with the administration on prior efforts to withdraw from Syria, said in a Wednesday statement: “While the Administration refuses to act against Turkey, I expect strong bipartisan support” for the sanctions bill.

“Most Members of Congress believe it would be wrong to abandon the Kurds who have been strong allies against ISIS,” he added. Multiple lawmakers from both parties have issued strong statements opposing the movement of U.S. troops out of Turkey’s way in Syria since the White House’s statement Sunday evening.

Trump on Wednesday expressed support for the proposed bill, adding that he would impose “far more than sanctions” on Erdogan’s regime in retaliation for attacking Kurdish U.S. allies.

Secretary of State Mike Pompeo noted in a Wednesday interview with PBS Newshour that while U.S. troops and their allies destroyed the ISIS caliphate, remnants of the terrorist group remain. “We will continue to be in a position to do what we need to do to keep the American people as safe as we possibly can from this threat,” he said.