The United States has drained much of its weapons stockpile, totalling up to billions of dollars, in its war on Iran, according to a New York Times investigation.

The weapons, as per the NYT, included over 1,200 Patriot interceptor missiles — each worth more than $4 million. According to the report, the US has “burned through around 1,100 of its long-range stealth cruise missiles built for a war with China, close to the total number remaining in the US stockpile”.

Also included in the stockpile used were over 1,000 Tomahawk cruise missiles — around ten times the US military’s annual stock.

Citing internal Defence Department estimates and congressional officials, NYT reported that over 1,000 Precision Strike and ATACMS ground-based missiles were used, “leaving inventories worryingly low”.

Further, around 1,100 JASSM-ER missiles were used — each worth around $1.1m — leaving only 1,500 in the military’s stock.

The report said that the existing situation had left the US military “less ready” to confront threats from Russia and China.

While the US has not yet disclosed the total number of munitions used in the war, officials told NYT that the 13,000 targets hit figure cited by the Pentagon masked the “vast number of bombs and missiles it used because warplanes, attack planes and artillery typically strike large targets multiple times”.

Citing two independent groups, the report said that total expense was between $28bn and $35bn, “or just under $1bn a day”. Defence officials told NYT that the first two days of war had led to the US military using $5.6bn worth of munitions.

As per the NYT, the Defence Department was “still waiting for Congress to approve additional funding before it can pay manufacturers to replenish the military’s drained supplies”.

However, despite the Trump administration announcing agreements with major defence contractors, officials told NYT that the Pentagon was “still scrambling to find the funding it needs”.

​“The US has many munitions with adequate inventories, but some critical ground-attack and missile-defence munitions were short before the war and are even shorter now,” Mark F. Cancian, a retired Marine Corps colonel and a senior adviser at the Centre for Strategic and International Studies, told the NYT. ​

Karoline Leavitt, the White House press secretary, said in a statement to the NYT that “the entire premise of this story is false.”

“The United States of America has the most powerful military in the world, fully loaded with more than enough weapons and munitions, in stockpiles here at home and all around the globe, to effectively defend the homeland and achieve any military operation directed by the commander in chief,” NYT quoted her as saying.

The report also cited a study by the American Enterprise Institute — compiled by Elaine McCusker, a senior Pentagon official during the first Trump administration — which said the total cost of the war so far has been between $25bn and $35bn.

The report also recalled that the USS Abraham Lincoln was moved from the South China Sea to the Middle East before the war began, and another aircraft carrier — USS George HW Bush — has been moved to the region as well.

The NYT also reported that the Patriot missiles from the THAAD system in South Korea had been moved as well.