Israeli soldiers take part in a military drill. File / AFP

The United States has spent a record of at least $17.9 billion on military aid to Israel since the war in Gaza began and led to escalating conflict around the Middle East, according to a report for Brown University's Costs of War project, released on Monday.

An additional $4.86 billion has gone into stepped-up US military operations in the region since the Oct.7, 2023, attacks, researchers said in findings.

That includes the costs of a Navy-led campaign to quell strikes on commercial shipping by Yemen's Houthis, who are carrying them out in solidarity with the fellow  group Hamas.

The report - completed before Israel opened a second front, this one against Hizbollah in Lebanon, in late September - is one of the first tallies of estimated US costs as the Biden administration backs Israel in its conflicts in Gaza and Lebanon and seeks to contain hostilities by Iran-allied armed groups in the region.

The financial toll is on top of the cost in human lives: Hamas killed more than 1,200 people in Israel a year ago and took others hostage. Israel's retaliatory offensive has killed nearly 42,000 people in Gaza, according to the territory's Health Ministry, which does not distinguish between civilians and combatants in its count.

At least 1,400 people in Lebanon, including Hizbollah fighters and civilians, have been killed since Israel greatly expanded its strikes in that country in late September.

The financial costs were calculated by Linda J. Bilmes, a professor at Harvard's John F. Kennedy School of Government, who has assessed the full costs of US wars since the Sept.11, 2001, attacks, and fellow researchers William D. Hartung and Stephen Semler.

Here's a look at where some of the US taxpayer money went:

Israel - a protege of the United States since its 1948 founding - is the biggest recipient of US military aid in history, getting $251.2 billion in inflation-adjusted dollars since 1959, the report says.

Even so, the $17.9 billion spent since Oct.7, 2023, in inflation-adjusted dollars, is by far the most military aid sent to Israel in one year.

The US committed to providing billions in military assistance to Israel and Egypt each year when they signed their 1979 US-brokered peace treaty, and an agreement since the Obama administration set the annual amount for Israel at $3.8 billion through 2028.

The US aid since the Gaza war started includes military financing, arms sales, at least $4.4 billion in drawdowns from US stockpiles and hand-me-downs of used equipment.

Much of the US weapons delivered in the year were munitions, from artillery shells to 2,000-pound bunker-busters and precision-guided bombs.

Expenditures range from $4 billion to replenish Israel's Iron Dome and David’s Sling missile defence systems to cash for rifles and jet fuel, the study says.

Unlike the United States' publicly documented military aid to Ukraine, it was impossible to get the full details of what the U.S. has shipped Israel since last Oct.7, so the $17.9 billion for the year is a partial figure, the researchers said.

They cited Biden administration "efforts to hide the full amounts of aid and types of systems through bureaucratic maneuvering.”

Associated Press