The House approved a measure on June 3 that could eventually require President Donald Trump to withdraw from military strikes in Iran, the first such step during the present conflict. This action followed about two weeks after the Senate advanced its own resolution with comparable though distinct provisions.

Legislative efforts involving the War Powers Resolution occur against a backdrop of public resistance to the conflict and its consequences, such as elevated fuel costs stemming from Iran's shutdown of the Strait of Hormuz following U.S. and Israeli strikes.

WATCH: House approves war powers resolution to halt military action against Iran

The House measure passed 215-208, as four Republicans - Reps. Thomas Massie of Kentucky, Tom Barrett of Michigan, Warren Davidson of Ohio and Brian Fitzpatrick of Pennsylvania - supported it alongside Democrats.

The Senate action on May 19 passed 50-47, with some senators absent. Four Republicans - Susan Collins of Maine, Lisa Murkowski of Alaska, Rand Paul of Kentucky and Bill Cassidy of Louisiana - backed it along with most Democrats except Sen. John Fetterman of Pennsylvania, who aligned with the majority of Republicans. The Senate step was procedural, releasing the measure from committee where it had been blocked.

"The Democrats are fueled by Trump Derangement Syndrome," Trump posted shortly after the House vote. "They would rather have our Country fail than give me another, of many, victories. The four Republicans, that's a whole other story - They're GRANDSTANDERS! They should be ashamed of themselves."

Critics of the war viewed the House and Senate actions as forward movement. Yet substantial obstacles remain before Congress can halt Trump's continuation of the conflict.

Here is a summary of upcoming actions.

What is the War Powers Resolution?

Article I, Section 8 of the U.S. Constitution grants Congress the authority to declare war. Congress last issued such a declaration at the outset of World War II during Franklin Roosevelt's presidency.

Since that time, presidents have typically launched military operations under their commander-in-chief powers without a formal war declaration.

In August 1964, President Lyndon B. Johnson sought congressional support to expand the U.S. involvement in Vietnam. He obtained it through the Tonkin Gulf Resolution, which cleared both chambers with minimal opposition in the Senate.

As the Vietnam conflict deteriorated, lawmakers grew frustrated with their limited influence over troop deployments abroad. In 1973, Congress enacted the War Powers Resolution over President Richard Nixon's veto.

The measure stipulated that, absent a war declaration, the president must notify Congress within 48 hours of committing forces to hostilities and must end such deployments within 60 days unless Congress approves an extension. An emergency extension of 30 days is possible if approval is withheld.

In recent years, congressional approval has often taken the form of an authorization for the use of military force. Trump has not submitted such a request to Congress.

During his first term, Congress approved two measures to constrain his war powers, though neither secured sufficient support to override a veto. One in 2019 sought to end U.S. backing for Saudi Arabia's operations in Yemen. The other in 2020 aimed to prevent further U.S. involvement after the strike that killed Iranian official Qasem Soleimani.

In Trump's second term, Republicans have controlled both chambers, and most have supported allowing him to conduct overseas military actions without explicit congressional authorization.

In June 2025, the Senate rejected advancement of a war powers resolution concerning Iran.

A later measure addressing Trump's use of force to detain Venezuelan leader Nicolas Maduro also fell short by a narrow margin.

What are the next steps?

The 60-day period for ending hostilities without congressional approval passed on May 1, yet Trump invoked a novel claim that military action had "terminated" due to a ceasefire with Iran. This overlooked ongoing periodic clashes, a sizable U.S. troop presence in the area and naval patrols near the strait.

The Senate requires 60 votes to reach a final vote on a war powers resolution assuming full participation; this would demand 10 additional votes beyond the May 19 tally, presenting a notable challenge.

"Party loyalty is a powerful force on Capitol Hill, and Republican leaders in the House and Senate will be strongly incentivized to let the Trump White House use military force without congressional approval," Matthew Green, a Catholic University political scientist, told PolitiFact last year.

If the Senate attains those 60 votes and approves the resolution, the chambers must reconcile differences between their versions, potentially necessitating further votes.

Should both chambers approve matching versions, the measure would still need the president's signature to become law, an outcome that appears improbable given Trump's stance on the conflict.

If Trump issues a veto, override would require two-thirds majorities in each chamber, far exceeding current support levels. No war powers resolution has ever succeeded in overriding a veto.

"If enacted, the joint resolution would require the removal of forces within 30 days of enactment, excluding steps of self-defense, unless specific congressional authorization for continued action is obtained," said Steven Smith, an Arizona State University political scientist.

Congress could pursue additional steps such as legislation to withhold funding for the war, though that too would likely face a veto and require two-thirds support in both chambers to override.

What are other possible endgames?

Mark F. Cancian, a senior adviser at the Center for Strategic and International Studies, indicated the matter might reach the courts. Since the War Powers Resolution took effect, courts have consistently avoided rulings on its constitutionality.

"If Congress were to pass the legislation, the Trump administration would develop a legal rationale for not complying, and the issue would end up in front of the Supreme Court," Cancian said. "That has been their general pattern."

Nevertheless, backers of the resolutions can find some value in partial successes even without full passage.

"So far, these congressional efforts have been thwarted, but they have had some political effect by keeping the issue in the news and emphasizing congressional and popular opposition to the war," Cancian said.

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