The United States has announced a fresh round of military and financial aid to Ukraine as Kyiv continues to battle Russian forces in the east and south of the country.

The Pentagon announced $1bn in military aid on Monday, and separately the World Bank said it was providing $4.5bn in budgetary assistance to the Ukrainian government, financed by the US government.

The new weapons package – the 18th of its kind since the war began in February – includes high mobility artillery rocket systems (HIMARS), mortar and artillery ammunition, Javelin anti-tank missile systems, explosives and demolition equipment.

“As we have made clear at every level of this administration, we’re committed to continued security assistance for Ukraine as they stand up to Russia’s unprovoked and unjustified invasion,” US Defense Department Under Secretary for Policy Colin Kahl told reporters on Monday.

The release of aid comes from the more than $40bn the US Congress allocated for aid to Ukraine earlier this year. Moscow has previously accused Washington of adding “fuel to the fire” of the conflict by providing weapons and long-range missiles to Ukraine.

Russia launched its all-out invasion of Ukraine on February 24 after a months-long standoff that saw Moscow amass troops near the Ukrainian borders as Russian President Vladimir Putin demanded an end to NATO expansion into former Soviet republics.