WASHINGTON, Mar. 28 (Reuters) - The United States' top general said on Thursday that Israel had not received every weapon it has asked for, in part because some of it could affect the U.S. military's readiness and there were capacity limitations.

Washington gives $3.8 billion in annual military assistance to Israel, its longtime ally. The United States has been rushing air defenses and munitions to Israel, but some Democrats and Arab American groups have criticized the Biden administration's steadfast support of Israel, which they say provides it with a sense of impunity.

"Although we've been supporting them with capability, they've not received everything they've asked for," said General Charles Q. Brown, the chairman of the U.S. Joint Chiefs of Staff.

"Some of that is because they've asked for stuff that we either don't have the capacity to provide or not willing to provide, not right now," Brown added, while speaking at an event hosted by the Defense Writers Group.

A spokesperson for Brown later on Thursday said his comments were in reference to "a standard practice before providing military aid to any of our allies and partners."

"We assess U.S. stockpiles and any possible impact on our own readiness to determine our ability to provide the requested aid," Navy Captain Jereal Dorsey said in a statement.

"There is no change in U.S. policy. The United States continues to provide security assistance to our ally Israel as they defend themselves from Hamas," Dorsey added.

More than 32,000 Palestinians have been killed in the Gaza Strip by Israel's devastating offensive, according to health authorities in the territory.

Israel retaliated following an attack by militant group Hamas on southern Israel, killing 1,200 people and abducting 253 hostages according to Israeli tallies.

The Israeli offensive prompted opposition from within Biden's Democratic Party, leading thousands to vote "uncommitted" for him in recent party presidential primaries.

U.S. Defense Secretary Lloyd Austin met with Israel Defense Minister Yoav Gallant in Washington earlier this week and the Pentagon said security assistance to Israel was discussed.

"It is a constant dialogue," Brown said.

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