(TNS) The U.S. said it will provide another $450 million in advanced weaponry and aid to Ukraine, the latest tranche in what has become a multibillion-dollar effort to help push back Russia’s invasion. 

The new package includes patrol boats, cannon shells, rocket systems and additional ammunition to “help Ukraine defend its democracy in the face of unprovoked Russian aggression,” National Security Council spokesman John Kirby told reporters Thursday. Kirby said U.S. security assistance since the war began now totals about $6.1 billion. 

The move comes just weeks after President Joe Biden announced $1 billion in new weapons and support, including high-technology rocket systems meant to allow Ukraine to hit Russian targets from as far as 80 kilometers (50 miles) away. After required training for Ukraine’s military, some of those weapons are now flowing into the country. 

With the war about to enter its fifth month, the conflict has transformed into a slow grind that’s largely centered in Ukraine’s east. Russian troops this week seized two more villages south of Lysychansk, in Luhansk, a stronghold Kyiv relies on in its defense in that area. 

According to a Pentagon statement, the new assistance includes four High Mobility Artillery Rocket Systems; 36,000 rounds of 105mm ammunition; 18 tactical vehicles to tow 155mm artillery; 1,200 grenade launchers; 2,000 machine guns; and 18 coastal and riverine patrol boats.

U.S. officials including Defense Secretary Lloyd Austin and General Mark Milley, head of the Joint Chiefs of Staff, have rejected criticism that new American and NATO weaponry is flowing into Ukraine too slowly to change the course of the war.