The cost of United States' war on Iran, that began on February 28, has now surpassed $37.5 billion, US defence secretary Pete Hegseth has said. The figure is an increase by nearly $8 billion since May estimates.Pete Hegseth asked Congress to approve the supplemental funding request, saying $67 billion of the proposed $87 billion package would be used to support military operations in the Gulf. (AP )"The estimate we have as of today is $37.5 billion," Hegseth told a Senate Appropriations Committee on Tuesday, AFP reported. He added that the amount also included some anticipated military operations and maintenance costs through September 30.Hegseth asked lawmakers to approve a supplementary $87 billion funding request for the Department of Defense. Of that amount, $67 billion would be earmarked directly for active operations across the Gulf, he said.ALSO READ | Trump promises Lebanon ‘respect it deserves’ as its President presents plan to disarm HezbollahWhat Pete Hegseth said“We live in a dangerous world,” Hegseth said, arguing that the funds were necessary to build force lethality and restore peace through strength, AP reported. “Without these funds, we face critical shortfalls that threaten our ability to simply pay our service members, rapidly replenish equipment and munitions, and sustain vital operations without disruption.”He described the request as a “generational investment” that would strengthen the US military and ensure it did not fall behind rival nations. He added that every dollar would be used to increase the “lethality” of US forces and reinforce “peace through strength.”“Rest assured that every dollar appropriated to the Department of War will be focused on building the lethality of our joint force, and reinforcing peace through strength,” Hegseth said.The hearing came as the US carried out an 11th consecutive night of strikes on Iranian targets and Tehran continued retaliatory attacks against US forces and allies in the region.ALSO READ | US hits Iran's Bushehr, Tabriz; Trump says strikes 'not finished', brent crude at a high: 10 updatesThe request comes on the heels of the White House asking Congress for a record $1.5 trillion general defence budget for the next fiscal year. Lawmakers on both sides of the aisle remained sceptical.War cost estimate increasesThe latest estimate represents an increase of nearly $8 billion from the Pentagon's last official assessment in May, when the war's cost was put at $29 billion. Earlier, Pentagon officials told lawmakers that the war had cost $11.3 billion during its first week, as per a New York Times report in March.Democratic lawmakers questioned the latest estimate. Two Democratic sources and another person familiar with the matter told CBS News that the actual cost could be significantly higher because the Pentagon's calculation did not include expenses such as rebuilding damaged US military bases.The hearing was also interrupted several times. Senator Patty Murray of Washington, the top Democrat on the committee, said that the war was “spiralling out of control again.”ALSO READ | 0, 100, 200: How Trump's latest generic medicines tariffs could affect India"My colleagues and I cannot and will not support rubber-stamping a request to bankroll this war and whatever other misadventures Trump wants to get us into next," Murray said, as per CBS. "The American people want to see a quick and strategic end to this war, not $70 billion of their tax dollars sent to keep it going."Senator Kirsten Gillibrand accused the Trump administration of seeking “unlimited money for bombs” even as many Americans struggled with rising living costs.It ended in a heated exchange between Hegseth and Democratic Senator Gary Peters, who called the defence secretary a "failure" and accused the administration of dragging the US into another “forever war.” “You, sir, are the failure,” Peters said. “Not the men and women who are on that frontline. … If there's a lack of a winning strategy, they're in harm's way, their leaders have failed them.”Hegseth responded, “Shame on you and others who call this a quagmire and a failure, and then you want to turn around and say you support the warfighter. Either you do or you don't.” He also accused him of suffering from “Trump derangement syndrome.”Fresh US strikes, Iran respondsHours after the hearing, the US launched another round of airstrikes on Iran, for the 11th straight night. Iranian state media reported air defence activity over Tehran early Wednesday.Explosions and interceptions were reported in the west, east and northeast of the capital. Strikes were also reported around Bushehr, home to one of Iran's nuclear power plants.ALSO READ | Trump threatens strike in Iran's Pickaxe Mountain, says the US is ‘not finished at all’US President Donald Trump warned that the US was “not finished” with Iran and suggested the next target could be Pickaxe Mountain, an underground nuclear complex near Natanz that Western intelligence agencies suspect houses an undeclared uranium enrichment facility."If we left right now, it would take Iran 20, 25 years to rebuild," Trump said. “We're not finished at all... we're not leaving right now.”