Speaker Mike Johnson on Tuesday called the War Powers Act "unconstitutional" amid a bipartisan push to check President Trump's authority to carry out unilateral military strikes on Iran.

Why it matters: Johnson's (R-La.) comments are his strongest signal yet that he's against an effort to use the law to assert Congress' authority to rein in the president's use of military force.

• "Many respected constitutional experts argue that the War Powers Act is itself unconstitutional," Johnson told reporters Tuesday.
• He added: "I'm persuaded by that argument. They think it's a violation of the Article 2 powers of the commander in chief. I think that's right."

Driving the news: Rep. Thomas Massie (Ky.) — the lone GOP sponsor of a resolution to limit Trump's ability to escalate in Iran — indicated he would back off his push to force a vote after Trump announced Monday that Israel and Iran had agreed to a ceasefire.

• But congressional Democrats are still forging ahead in an effort to send a broader message about Congress' authority to declare war.
• A vote on Sen. Tim Kaine's (D-Va.) war powers resolution could happen as soon as Wednesday, although a decision to delay a planned Tuesday afternoon Iran briefing could affect timing.

Catch up quick: Johnson and many other Republicans have insisted that Trump had the authority to take action against Iran — and dismissed lawmakers who have demanded that Trump seek congressional approval.

• "The strikes on Iran's nuclear facilities were clearly within President Trump's Article 2 powers as commander in chief. It shouldn't even be a dispute," Johnson said Tuesday.

The other side: Democrats, and some Republicans, have argued the president violated the Constitution when he carried out strikes on Iran's nuclear facilities without Congress' explicit authority.

• Johnson had already indicated he planned to block Massie's privileged resolution, which has over 50 Democratic co-sponsors.