WASHINGTON - The White House approved Thursday a new package of up to US$600 million (S$845 million) in additional military aid for Ukraine, as Washington moves to support Kyiv's counter-offensive against Russia's invasion force.

Since Russia invaded Ukraine in February, the United States has provided more than US$15 billion (S$21 billion) in military assistance to Kyiv.

This marks the 21st time the Biden administration has drawn down US inventories to send weapons to Ukraine since September 2021.

The previous drawdown, for US$675 million, was just a week ago.

The Defence Department said the latest US$600 million in assistance includes ammunition for the Himars rocket systems; 1,000 "precision-guided" 155mm artillery shells; 36,000 105mm shells; as well as mine-clearing equipment.

"Together with our allies and partners, we are delivering the arms and equipment that Ukraine's forces are utilising so effectively as they continue their successful counter-offensive against Russia's invasion," US Secretary of State Antony Blinken said in a statement.

The US and its allies want to keep the weapons flowing for that counter-offensive.

"We are moving in only one direction - forward and toward victory," Ukrainian President Volodymyr Zelensky said Wednesday during a surprise visit to the strategic city of Izyum.

Nato Secretary-General Jens Stoltenberg said on Friday Ukraine’s counter-attack against Russian troops had been very effective but warned nations should prepare for the long haul as this did not signal the beginning of the end of the war.

“It is of course extremely encouraging to see that Ukrainian armed forces have been able to take back territory and also strike behind Russian lines,” Mr Stoltenberg told BBC radio.

“At the same time, we need to understand that this is not the beginning of the end of the war, we need to be prepared for the long haul.” AFP, BLOOMBERG, REUTERS