Congress, by and large, is not pleased with President Trump’s recent decision to withdraw US troops from northern Syria — but there’s little that lawmakers can do to reverse it besides putting pressure on Trump.

While the House has already passed a resolution that condemns the president’s decision — Senate Majority Leader Mitch McConnell has even penned an op-ed expressing his opposition — the power to move this contingent of American troops lies strongly with the executive branch, as dictated by the Constitution.

“Constitutionally, because the president is commander-in-chief, there’s little Congress can do to compel the president to use armed force or to support belligerents with combat troops if the president doesn’t want to do so,” Tufts University’s Fletcher School law professor Michael Glennon told Vox. “Congress can check an exercise of military power by the president that it doesn’t like, but it’s hard to force the president to use military power that it does want exercised.”

As a result, lawmakers in both the House and Senate are faced with limited options in how they’re able to confront Trump and his decision to withdraw US troops from northern Syria. Trump’s move has since spurred military action from Turkey and led to attacks on the United States’ Kurdish allies in the region.

Thus far, members of Congress have used a couple methods to convey their disagreement: There’s been significant public outcry from lawmakers on both sides of the aisle. Trump supporters have focused on convincing him to undo this decision and Democrats have reached out to US allies on their own.

Increasingly, both Democrats and Republicans are turning to an area where Congress has a bit more jurisdiction, even if it is an indirect tool: imposing sanctions on Turkey.

“Under Congress’s power over foreign commerce, Congress can impose sanctions on countries and individuals that engage in activities it finds repugnant,” Glennon said.

Members in both chambers are now proposing different versions of sanctions legislation that would curb Turkey’s access to arms and other resources. But partisan differences — not to mention the uncertainty around a ceasefire agreement — cast doubt around whether these bills would actually advance. Turkey and Russia announced an agreement establishing their joint jurisdiction over Syria’s northern border on Tuesday.

For now, lawmakers are still moving ahead with their legislative efforts. House Foreign Affairs Committee Chair Eliot Engel (D-NY) told Vox he expects a Turkey sanctions bill to come to the floor next week in the lower chamber.

“Considering we just got back from Afghanistan late yesterday, we need some time to concentrate — we want to do it right,” he said, referring to an unannounced trip that he, House Speaker Nancy Pelosi, and a handful of other high-level members made to the Middle East this weekend. “We’re going to have a Turkey sanctions bill and we’re going to have an Armenian genocide bill, both of which I’m sure the government of Turkey is not happy with, but then again, we’re not very happy with the government of Turkey.”

In the Senate, a subset of Republicans are also working on sanctions against Turkey, though the prospects seem a little less promising. Foreign policy is one of the few issues that lawmakers on both sides of the aisle have occasionally found themselves united on during Trump’s presidency, but whether their concerns about his Syria withdrawal ultimately translate to action remains an open question.

There are a lot of sanctions bills floating around the Capitol

In both chambers, there’s been bipartisan support for sanctions on Turkey, so much so that there are at least five bills in some stage of development. In the upper chamber, that includes a bill that’s been introduced by Trump ally Sen. Lindsey Graham (R-SC), the chair of the Senate Judiciary Committee.

Graham and Sen. Chris Van Hollen (D-MD) have proposed legislation that would target Turkey’s access to military equipment and energy resources; Sen. Rand Paul (R-KY) has a bill specifically focused on arms access; and Sens. James Risch (R-ID) and Bob Menendez (D-NJ) have their own, more wide-ranging legislation, which would restrict weapons sales and authorize additional humanitarian aid to Syria.

“We’re working on it,” Risch told reporters on Tuesday, when pressed on the status of the legislation’s advancement.

As in the Senate, there are also a couple sanctions options floating around the House. The House Foreign Affairs Committee has been working on its own Turkey sanctions bill for the past couple weeks, with a likely floor vote coming next week. Members of the committee told Vox they want to see something as soon as possible.

In addition to that bill, House Republicans introduced their own sanctions legislation last week. The GOP bill would ban US military assistance to Turkey and place a similar crackdown on any person or group that gives “financial, material or technological support” to Turkey’s military.

Increasingly, this appears to be the main avenue for both Republicans and Democrats to channel their opposition toward Trump’s actions, but no legislation is scheduled for a vote just yet — or even necessarily set to make it to the floor in the Senate.

Republicans aren’t happy with Trump’s actions, but could be reluctant to move additional bills

While Republicans are speaking out against Trump’s actions in the Middle East, it’s yet to be seen how forcefully they actually push back. Historically, foreign policy has been one of the main areas the party has been willing to actually break with Trump, largely because it’s an area that’s viewed as less of a political priority for the president.

This dynamic has played out before: Congress has voted repeatedly to end US backing for Saudi Arabia in a conflict in Yemen, and there’s been Senate support for sanctions against Russia in the wake of revelations about interference in the 2016 election.

But in the case of Turkey, McConnell has warned against moving too quickly on sanctions, a sign that bills in the upper chamber may not see further action anytime soon.

“If we’re going to use sanctions against a democratic ally, we need to be careful,” the majority leader said in a floor statement on Tuesday. McConnell also announced the introduction of his own resolution, which criticizes Turkey’s attacks on Syria, calls for the preservation of troops in the region “where practical,” and opens the door to potentially using sanctions as a pressure point.

Although many Republicans have been willing to criticize the president on Syria — and foreign policy in general — the push to impose sanctions against Turkey, if the administration lifts its own, would take that opposition much farther than their existing criticism does. It’s possible lawmakers would attempt to skirt a direct confrontation like this, and sanctions efforts could wither in the upper chamber as a result.

The vast majority of House Republicans also backed last week’s bipartisan bill condemning Trump’s withdrawal of American troops from northern Syria, and supported asking for a plan to combat a potential resurgence of ISIS. The fact that Republican leaders were united with Democrats on last week’s bill may have been a sore spot for Trump, who had an explosive meeting with top Republicans and Democrats in Congress shortly after the vote was taken last Wednesday.

Even that pushback, however, has its limits. While House Republicans have also been framing the pulling out of US troops from the region as an abandonment of the Kurds, they’ve also been careful to avoid directly criticizing Trump. Cheney, who introduced the Turkey sanctions bill last week, even suggested Turkey may have moved its troops into Syria because of Democrats’ impeachment inquiry.

“What the Democrats are doing themselves to try to weaken this president is part of this,” Cheney said during a Fox News interview. “It was not an accident that the Turks chose this moment to roll across the border.”

While the Syria-Turkey news marks a significant break between Trump and House Republicans, some Democrats don’t think it will extend to other issues.

“Look, I think there’s bipartisan concern about what the president has done,” House Rules Committee Chair Jim McGovern (D-MA) told Vox. “I’m glad Republicans are finding a backbone in speaking out, but where have they been? They have enabled this president to diminish our standing in the world, but I’m happy that many of them are speaking out now.”