A prominent Democratic senator has introduced a bill to require United States President Donald Trump to first seek authorisation from Congress before ordering military strikes against Iran, Aljazeera reports.

The measure, put forward by Virginia Senator Tim Kaine on Monday, came amid growing calls by pro-Israel groups for the US to join the Israeli bombing campaign against Iran as the attacks between the two countries intensify.

“I am deeply concerned that the recent escalation of hostilities between Israel and Iran could quickly pull the United States into another endless conflict,” Kaine said in a statement.

“The American people have no interest in sending service-members to fight another forever war in the Middle East. This resolution will ensure that if we decide to place our nation’s men and women in uniform into harm’s way, we will have a debate and vote on it in Congress.”

The bill invokes the War Powers Resolution of 1973, passed during the Vietnam War to constrain unilateral presidential powers to engage in military hostilities.

The US Constitution gives Congress the power to declare war, but successive US presidents have used their positions as the commander-in-chief of the armed forces to mobilise troops, initiate attacks and start conflicts without clear congressional authorisation.

Kaine’s proposal adds to the pressure Trump is facing from antiwar advocates in both major parties, advocates said.

Hassan El-Tayyab, legislative director for Middle East policy at the Friends Committee on National Legislation, said the bill sends a message to Trump against going to war with Iran and to the Israelis that “they’re not going to just get blank-cheque US support”.

It could also gauge the level of opposition to war with Iran in Congress, especially among Republicans. A growing contingency of right-wing lawmakers has been warning Trump against being dragged into a conflict that they said does not serve US interests.

‘De-escalatory signal’

While Trump’s Republican Party controls both houses of the US Congress, the resolution may pass if conservative lawmakers who oppose foreign military interventions join the Democrats in backing it.

To become law, the bill needs to pass in the Senate and House of Representatives and be signed by Trump, who would likely block it. But Congress can override a presidential veto with two-thirds majorities in the House and the Senate.

During his first term, Trump successfully vetoed two war powers resolutions, including a 2020 bill that aimed to curb his authority to strike Iran, which was also led by Kaine.

El-Tayyab said the 2020 push helped warn Trump against further strikes against Iran after the killing of top Iranian General Qassem Soleimani despite the presidential veto, adding that the current measure may have a similar effect.

“Even if it passes and Trump vetoes it, it still sends a de-escalatory signal, and it reminds the administration that only Congress can declare war,” El-Tayyab told Al Jazeera.

Trump has not ruled out US strikes against Iran. “We’re not involved in it. It’s possible we could get involved,” he told ABC News on Sunday.

At the same time, the US president has called for ending the war.

Israel launched a bombardment campaign against Iran on Friday, targeting military and nuclear sites as well as residential buildings and civilian infrastructure, killing dozens of people, including top military officials and nuclear scientists.

The assault came just days before US and Iranian negotiators were to meet for a sixth round of nuclear talks in Oman.

Iran has responded with hundreds of ballistic missiles, many of which have penetrated Israel’s air defences, causing widespread damage across the country.