Washington — Defense Secretary Pete Hegseth told lawmakers Tuesday the U.S.-Iran war has cost about $37.5 billion so far, as the Trump administration asks Congress to approve tens of billions of dollars in additional Pentagon funding to help underwrite the cost of the war. Hegseth testified to the Senate Appropriations Committee following an escalation in the war with Iran in recent days. Under questioning from Illinois Democratic Sen. Richard Durbin, Hegseth said the administration estimates that the Iran conflict has cost $37.5 billion so far. A Pentagon official testified in mid-May that the war had cost about $29 billion at that point. The deaths bring the total number of service members killed since the war began in February to 18.