As Israel’s military onslaught on Gaza continues into its 24th day, a senior US defense official announced today that the US has allowed Israel to tap into an munitions stockpile to resupply the Israeli military with weapons.

The munitions were part of the program called War Reserves Stock Allies-Israel (WRSA-I), which locally stores weapons for the US, and can be used by Israel in case of emergency. Israel, however, did not state an emergency situation when it requested use of the munitions.

“The United States is committed to the security of Israel, and it is vital to US national interests to assist Israel to develop and maintain a strong and ready self-defense capability,” said Rear Admiral John Kirby, the Pentagon's press secretary, in a statement today. "This defense sale is consistent with those objectives."

Kirby added that White House approval was not required for the use of US weapon stockpiles by Israel.

Although it was not confirmed if these weapons would specifically be used in the current offensive in Gaza, it highlights the close relationship that exists between Israeli and US military cooperation and interests.

The use of US weapons to aid Israel’s military comes at a time of mounting criticism towards Israel’s offensive in the Gaza Strip, which has already killed more than 1,300 Palestinians, most of whom were civilians. Specifically, it calls into question the role of the US in the conflict, especially after President Obama called for a unilateral ceasefire and an end to hostilities on both sides.

“There is nothing unique about this,” Tony Cordesman, a military strategy expert at the Center for Strategic and International Studies, told VICE News. “Since 1997 the US has provided Israel with military grants that range from about 2 to 3 billion a year.”

The presence of a munitions stockpile in Israel serves as more of a contingency plan than to serve in case of a real-time emergency, added Cordesman. The weapons being stored were reportedly 40mm grenades and 120mm mortar to be used by Israel in case they run out.

The US also funds a substantial portion of Israel’s Iron Dome defense shield, which has been used to intercept Hamas rockets shot into Israel. Congress recently added another $225 million onto a spending bill to fund the Iron Dome.

Today, Israeli Prime Minister Benjamin Netanyahu vowed to escalate Israel's military onslaught on the Gaza Strip to destroy all Hamas tunnels. He added that he would not agree to any ceasefire that limited Israel's ability to do so.