The Pentagon on Wednesday announced a new security assistance package worth up to $175 million for Ukraine, including depleted uranium ammunition for Abrams tanks, the first time the U.S. is sending the controversial armor-piercing munitions to Kyiv.

Reuters was first to report last week that the rounds, which could help destroy Russian tanks, would form part of a new military aid package for Ukraine.

On Wednesday, the Pentagon said the military aid would also include anti-armor systems, tactical air navigation systems and additional ammunition for High Mobility Artillery Rocket Systems (HIMARS).

The announcement coincides with top U.S. diplomat Antony Blinken’s arrival in Kyiv in a gesture of support as Ukraine’s counteroffensive against Russian forces grinds into its fourth month with only small gains.

Blinken announced new aid for Ukraine totaling more than $1 billion in a visit to Kyiv, including over $665 million in new military and civilian security assistance and millions of dollars in support for Ukraine’s air defenses and other areas.