WASHINGTON ― U.S. House and Senate lawmakers are readying bills to sanction and potentially ban U.S. arms exports to NATO ally Turkey to punish it over military operations in northern Syria against U.S.-backed Kurdish forces who helped fight the Islamic State in Iraq and Syria.

The action comes after France, Germany, Finland, the Netherlands and Norway announced last week they would suspend arms sales to Turkey. French and German officials announced their bans Saturday.

The U.S. House bill was being finalized late last week, but the Senate bill it corresponds to would clamp sanctions on the U.S. assets of Turkish President Recep Tayyip Erdogan and sanction foreign military sales to Turkey, according to an outline of the Senate bill. The two bills are expected to be introduced formally this week, as Congress returns from a two-week recess.

The measures effectively rebuke President Donald Trump’s abrupt decision to pull U.S. troops from the region. Soon after their withdrawal, Erdogan commenced air and ground assaults on Syrian Kurdish fighters who’ve been helping the U.S. battle Islamic State extremists there, which numerous lawmakers and others had warned would happen.

“What we’re seeing on the ground right now is absolutely sickening, it’s absolutely shameful that President Trump allowed Turkey to begin killing the Syrian Kurds, which are our ally in the fight against ISIS ― which is why you see this bipartisan uproar,” Sen. Chris Van Hollen, D-Md., a co-sponsor of the Senate bill with Sen. Lindsey Graham, R-S.C., said. Van Hollen made the comments on “Fox News Sunday.”

“Congress will call on the president to do the right thing and since we can’t count on that, we will have this bipartisan legislation that will impose very stiff sanctions on Turkey until they stop their aggression and withdraw their forces.”

Graham said in a tweet Sunday that sanctions have “strong bipartisan support,” calling it “imperative that we do not allow Turkey’s aggression to lead to the destruction of a valuable ally — the Kurds — and the reemergence of ISIS.”

The Senate measure would take effect immediately, and its restrictions would be lifted only when the Trump administration certifies that Turkey has ceased its operations and withdrawn its forces from the region.

Treasury Secretary Steven Mnuchin has held out the possibility of quick action to impose economic sanctions on Turkey, a move that Trump has repeatedly threatened if the Turks were to push too far into Syria.

“If we go to maximum pressure, which we have the right to do — at a moment’s notice the president calls me up and tells me — we will do this,” Mnuchin said Sunday on ABC’s “This Week.” “We could shut down all U.S. dollar transactions with the entire government of Turkey. ... That is something we may do, absolutely.”

The administration threatened sanctions against Turkey earlier this year for its purchase of the Russian S-400 air defense system, but never followed through.

The chairman of the House Foreign Affairs Committee, Rep. Eliot Engel, D-N.Y., said the U.S. and its NATO partners should consider expelling Turkey from the alliance. “How do you have a NATO ally who’s in cahoots with the Russians, when the Russians are the adversaries of NATO?”

Turkey launched its operation into northern Syria on Wednesday, after the U.S. announced it was pulling troops from the area. It argues the offensive against the Kurdish-led Syrian Democratic Forces, which it links to terror organizations, will allow it to create a safe zone and allow Syrian refugees it hosts to relocate.

Trump is under pressure as even some of his staunchest Republican supporters have sharply criticized his decision to withdraw U.S. troops and urged him to reconsider. Some regard it as a betrayal of the U.S.-armed Kurdish fighters who have, at great cost, partnered with U.S. forces against the Islamic State group since 2015.

Forces on both sides of the conflict are expected to be using American weaponry, as the U.S. has supplied Turkey with munitions and attack aircraft and Kurdish-led forces with arms and ammunition, according to the Center for International Policy.

House GOP Conference Chair Liz Cheney, R-Wyo., plans to introduce the House version of the sanctions legislation with nearly 30 of her House Republican colleagues, to include Republican Leader Rep. Kevin McCarthy, Republican Whip Rep. Steve Scalise and House Armed Services Committee ranking member Rep. Mac Thornberry.

“These sanctions are not only a response to the Erdogan regime’s violent attacks in northern Syria,” Cheney, who is also a member of the House Armed Services Committee, said in a statement last week. “Congress has long had concerns about the regime’s cooperation with U.S. adversaries, such as Russia. If Turkey wants to be treated like an ally, it must begin behaving like one. They must be sanctioned for their attacks on our Kurdish allies.”

At least one House Democrat, Rep. Ro Khanna, is also calling for arms sales to Turkey to be suspended, and criticized Trump for not using the sales and economic aid as leverage to dissuade Erdogan from his invasion. Trump, Khanna said in a tweet, “should work with Congress on sanctions + suspending arms sales.”

On the flip side, some lawmakers like Sen. Chris Murphy, D-Conn., said the U.S. needs quicker action to prevent a humanitarian catastrophe.

“Spare me the nonsense on sanctions,” Murphy, who sits on the Foreign Relations Committee, said in a tweet Sunday. “People are being slaughtered RIGHT NOW. Bombs are dropping on children RIGHT NOW. Instead of drafting sanctions bills, Republicans should use their massive leverage over the President to get him to change course. RIGHT NOW.”

If the U.S. were to join France and Germany, it would cut off Turkey from three of the top five arms exporters on the globe, according to Stockholm International Peace Research Institute rankings. Russia and China are the other top two arms exporters.

Turkey imports 60 percent of its weapons from the U.S., followed by Spain and Italy, and it is the world’s 13th biggest arms importer. But Turkey’s relationship with Washington has been threatened recently after Turkey began accepting delivery of the S-400, which the White House said would help Russian intelligence.

According to the Center for International Policy, Turkey maintains 333 combat aircraft, including the F-5 and F-16; 2,400 tanks, including the M-1 and M-48; 333 M-113 armored personnel carriers, and 31 C-130 transport aircraft. In 2015, the U.S. sold Ankara $380 million in Joint Direct Attack Munitions.

Erdogan is surely worried U.S. sanctions could be crippling to the vulnerable Turkish economy, but a suspension of U.S. arms sales would matter less practically than it would geopolitically, according to Stephen Flanagan, senior political scientist at the RAND Corporation in Washington.

“It’s certainly another blow to the relationship,” Flanagan said, adding that after its acceptance of the S-400, “Turkey has lost any friends that it had on Capitol Hill, and that’s showing up now."

The Associated Press contributed to this report.

Joe Gould was the senior Pentagon reporter for Defense News, covering the intersection of national security policy, politics and the defense industry. He had previously served as Congress reporter.

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