The United States' war in Iran has cost $29 billion so far, a senior Pentagon official said on Tuesday, an increase of $4 billion from an estimate provided late last month.
With just six months before midterm elections in which President Donald Trump's Republicans may face an uphill battle to keep their House majority, Democrats are riding high in public opinion polls as they attempt to link the war with cost of living issues.
On April 29, the Pentagon said the war at that point had cost $25 billion.
Jules Hurst, who is performing the duties of the comptroller, told lawmakers on Tuesday that the new cost included updated repair and replacement of equipment and operational costs.
"The joint staff team and the comptroller team are constantly looking at that estimate," Hurst said.
He was speaking alongside Defence Secretary Pete Hegseth and Chairman of Joint Chiefs of Staff, General Dan Caine.
It is unclear how the Pentagon arrived at the $29 billion figure.
A source told Reuters in March that Trump's administration estimated the first six days of the war had cost at least $11.3 billion.

Bahrain, Kuwait, Jordan face renewed Iranian attacks after US hits Iran's south
Lebanese army enters southern town after Israeli withdrawal, in first test of US-brokered deal
Kuwait lodges formal protest with Iran over tanker attack; ministry says power station fires contained
Russian attack kills three in Ukraine's Zaporizhzhia, officials say
Fires in Spain and France, hail in Balkans; Europe's erratic weather persists
