The war involving the United States and Iran has cost Washington $29 billion so far, a senior Pentagon official said on Tuesday, marking a $4 billion increase from an estimate released late last month.

The updated figure comes as the conflict becomes a major political issue ahead of the US midterm elections, with President Donald Trump and the Republican Party facing growing criticism over the management of the war and its economic consequences, The Caspian Post reports, citing Reuters.

The Pentagon previously estimated on April 29 that total spending related to the war stood at $25 billion.

Jules Hurst, who is performing the duties of comptroller, told lawmakers that the revised amount includes additional expenses connected to equipment replacement, repairs, ongoing military operations and wider battlefield-related costs. He appeared before lawmakers alongside Defence Secretary Pete Hegseth and Chairman of the Joint Chiefs of Staff Dan Caine.

“The joint staff team and the comptroller team are constantly looking at that estimate,” Hurst said.

The Pentagon did not provide a detailed explanation of how the $29 billion figure was calculated. However, a source said in March that the Trump administration had estimated that the first six days of the conflict alone cost at least $11.3 billion.