The Pentagon is halting the delivery of some U.S. weapons to Ukraine that are crucial in its battle against Russia. This comes at a time when Russia has stepped up its attacks against Ukraine.

Chloropicrin is banned in war under the 1993 Chemical Weapons Convention (CWC), to which Russia is a signatory. Russia is already widely using tear gas, the Dutch defense ministry said, and called the deployment of chloropicrin a "grave violation" of the CWC.

President Donald Trump complained Thursday that the United States provided too many weapons to Ukraine under the previous administration, his first public comments on the pause in some shipments as Russia escalates its latest offensive.