Pentagon estimates the U.S. cost of the Iran war has reached nearly $29 billion amid rising scrutiny and political tensions.

US Defense Department tells Congress $4 billion jump from previous estimate is due to equipment upkeep, as Democrats accuse White House of futile and opaque spending on conflict

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.