US Senator Tim Kaine says he has “serious constitutional concerns” that the White House may exceed the 60-day limit for military action in Iran without Congressional approval, Al Jazeera reports.

Speaking at a Senate Armed Services Committee hearing, Pentagon chief Pete Hegseth has been pressed on whether the Trump administration intends to seek authorisation.

Under the War Powers Act of 1973, a US president can wage war without Congress for only 60 days — a deadline the Iran conflict is set to hit tomorrow. Hegseth, however, said the fact that the US has reached a ceasefire with Iran gives the administration more time.

“We are in a ceasefire right now, which [in] our understanding means the 60-day clock pauses or stops in a ceasefire,” he tells the Senate committee.

Kaine has responded, “I do not believe the statute would support that.”