US Senate Democrats blocked a $1.15 trillion annual defence policy bill on Tuesday, citing ‌frustration with the Iran war and President Donald Trump’s failure to consult with Congress about his decision to send US forces into the conflict.

“Trump started this war without authorisation, without a strategy, and without an exit,” Senator Chuck Schumer of New York, the Senate’s Democratic leader, said in ​a Senate speech announcing he would vote no.

The procedural vote on the National Defence Authorisation Act, or NDAA, failed. ​

Even though the yes votes outnumbered no votes by 50-46, the bill fell short of the ⁠60 votes needed to move ahead in the 100-member Senate.

The vote was along party lines. Every Republican voted in favour ​of moving ahead except for the chamber’s Republican majority leader, John Thune of South Dakota, who voted no under Senate rules ​only in order to enter a motion to reconsider.

The bill had been expected to stall after nine Democratic members of the Armed Services Committee voted against the NDAA when the panel considered it last month.

The NDAA typically passes with strong bipartisan support.

Democrats are concerned that authorising ​a huge Pentagon budget would be seen as approval of the war on Iran that began with strikes by the ​US and Israel on February 28.

The vote came just as the Trump administration said it had reimposed a naval blockade of all Iranian ports ‌in the ⁠latest escalation of the conflict and began a fresh round of strikes.

Democrats also object to the Trump administration’s push to increase military spending to a total of $1.5 trillion, even as social programmes for Americans are being cut.

Besides the $1.15 trillion authorised in the NDAA, Trump has asked for another $350 billion from Congress under the budget reconciliation process, which would allow the funding to ​pass without Democratic support.

In remarks ​urging support, Thune accused Democrats ⁠of putting politics ahead of security.

“It’s the bill that helps ensure our military is ready today and prepared for tomorrow,” he said.

This year’s NDAA authorises an unprecedented $1.15 trillion for defence, determining ​everything from how many ships, aircraft and missile systems are bought to pay raises for ​the troops and ⁠how to address geopolitical threats.

Historically seen by both parties as “must-pass legislation,” the NDAA is one of the few major bills that always passes, having become law annually for more than six decades.

Despite the setback, it is early in the NDAA process.

Each year, ⁠the House ​of Representatives and Senate pass their own versions of the NDAA, before ​Armed Services committee negotiators reach a compromise version that then comes up for a vote in each chamber.

If the compromise version passes, it would be sent ​to the White House for President Donald Trump to sign into law or veto.