A $1 billion security assistance package was announced by the Biden administration on Monday.
The 18th military aid package will bring the U.S. commitment to almost $10 billion.
The package includes more than one million rounds of 155mm, 120mm, and 120mm mortars, as well as 20,000 rounds of 120mm mortars for NASAMS.
The HIMARS are designed to shoot missiles from a mobile truck and have sat high on Ukrainian wish lists.
1,000 Javelins will be sent by the Pentagon, as well as hundreds of AT4 anti-armor systems, 50 armored medical treatment vehicles, anti-personnel munitions, explosives and demolition equipment.
The largest Ukraine assistance package was announced on June 15 but it was made up of a mixture of presidential authority and the security assistance initiative. The weapons come from U.S. inventories, according to Monday's package.
Secretary of State Antony Blinken said in a statement that they will consult closely with Ukraine and surge additional systems and capabilities to make a difference on the battlefield.