STORY: Senior Pentagon official Jules Hurst on Tuesday told lawmakers that the United States' war in Iran has cost the country $29 billion so far, an increase of $4 billion from an estimate provided late last month.

HURST: "So at the time of testimony from the ask, it was $25 billion, but the Joint staff team of the consular team were constantly looking at that estimate. So now we think it's closer to 29. That's because of updated repair and replacement of equipment costs and also just general operational costs to keep people in theatre."

It is unclear how the Pentagon arrived at the $29 billion figure. 

This all comes just six months before midterm elections in which President Donald Trump's Republicans may face an uphill battle to keep their House majority, 

Democrats, meanwhile, are riding high in public opinion polls as they attempt to link the war with cost of living issues, including gasoline prices which have seen a roughly 50% increase across the U.S..

On Monday, Trump said a ceasefire was "on life support" as Tehran rejected a U.S. proposal to end the conflict and hope for a peace deal dwindles.