• Since Russia invaded Ukraine, the US has sent lots of weaponry to the eastern European nation. 
  • Among those are M777 Howitzers and the 155mm ammunition rounds for the weapons. 
  • But this has depleted the US's own stockpiles of the munitions, The Wall Street Journal reported.

The US has provided Ukraine with so much weaponry to fend off Russia's unprovoked invasion that Pentagon stockpiles for some munitions are "uncomfortably low," according to the Wall Street Journal.

The low levels of 155mm ammunition rounds — which are fired from US-made M777 Howitzers — have some officials especially concerned, the Wall Street Journal reported on Monday.  

An anonymous defense official told the Journal that the level of 155mm ammunition rounds in US stockpiles hasn't reached critical levels, but it's "uncomfortably low" and "is not at the level we would like to go into combat."

Though the US isn't engaged in any major conflicts at the moment, the Journal reported, the American military used a howitzer just last week to attack Iranian-backed groups in Syria. 

Howitzers are towable large artillery weapons that can strike targets miles away. As of August 24, the US has committed to sending 126 M777 Howitzers to Ukraine, and up to 806,000 155mm artillery rounds for the weapons, according to the Pentagon.  

The US last week included up to 245,000 rounds of 155mm artillery ammunition in a $2.98 billion military aid package for Ukraine — the largest single collection of security assistance committed to the eastern European country since Russian forces invaded in late February.  

Aside from the howitzers and their ammunition, the US has also sent Ukraine a long list of other military supplies since Russia invaded in February, including mortar rounds, rocket systems, drones, counter-artillery capabilities, air defense systems, and personnel equipment. 

Read the original article on Business Insider