On Tuesday, the House of Representatives unanimously passed legislation to impose new sanctions on the Syrian government of Bashar al-Assad and its allies, and those who do business with them. The move comes a month after President Donald Trump’s announcement to withdraw troops from Syria, and as some Arab governments are thawing relations with the Assad regime, which has all but secured a military victory after nearly eight years of war. The measure has been passed by the House twice in previous sessions, and a companion bill currently remains pending in the Senate.

House Foreign Affairs Committee Chair Eliot Engel, D-N.Y., reintroduced the standalone version of the Syria bill, H.R. 31, which passed under fast-track procedures. On the Senate side, the bill is one provision rolled into a foreign policy-related package called the Strengthening America’s Security in the Middle East Act, with Florida Sen. Marco Rubio as a lead sponsor. Senate Democrats blocked the bill — designated as S.1, which symbolizes heightened importance — on the grounds that Congress should reopen the government before considering unrelated legislation.

The Caesar Syria Civilian Protection Act is named after the whistleblower who defected from the Assad regime and smuggled tens of thousands of photos of those tortured to death in regime prisons.

The current version of the bill imposes sanctions on anyone engaging in “significant financial, material, or technological support to, or knowingly engages in a significant transaction with” the Syrian government or the governments of Russia and Iran in Syria. It includes an exception for nongovernmental organizations operating in Syria, and it directs the president to come up with a plan regarding the delivery of humanitarian aid to Syrians in need.

The Syrian government has been courting investors to help rebuild parts of the country decimated throughout the multi-pronged Syrian war. Reconstruction plans have largely focused on areas destroyed by Syrian and Russian bombs, like parts of Damascus and Homs, and not cities like Raqqa, which the U.S.-led coalition flattened in its fight against the Islamic State. Western governments have said they will not contribute to reconstruction efforts until progress is made toward a peaceful settlement to the war. The European Union this week imposed a new round of sanctions on business executives and entities doing business with the Assad regime.

Some antiwar groups, including the Friends Committee on National Legislation and Just Foreign Policy, oppose the Caesar bill, considering it a rebuke to the Trump administration’s plans to withdraw U.S. troops from Syria. “FCNL opposed the original draft of the Caesar Syria Civilian Protection Act [the Rubio-Engel Syria-Iran-Russia sanctions bill] in 2017,” the group said in a statement before the House vote. “Since that time, important changes to the legislation have been made, but our core concerns remain the same. In light of President Trump’s recent decision to begin withdrawing U.S. troops from Syria, support for this bill is widely being interpreted as an appeal for continued military involvement.”

Chad Brand, a government relations officer at the Syrian American Council, which consulted lawmakers throughout the drafting of the bill, rejects the criticism. He noted that the sanctions don’t endorse any kind of military action and are in no way tied to attempts to keep U.S. forces in the war-torn country.

“This isn’t targeted against the Syrian people, it isn’t targeting humanitarian aid,” Brand said. “If you look specifically at Section 3, to be precise, there’s waiver language that’s in there to ensure that NGOs are not penalized regarding the distribution of aid in the regime areas.”

The White House issued a statement in support of the bill last November. “This bill will help provide additional leverage to achieve the United States government’s objectives to de-escalate the military conflict and support the United Nations-led peace process and a transition to a government in Syria that honors the will of the Syrian people, respects the rule of law and human rights, and peacefully co-exists with its neighbors in the region,” the White House wrote.