Himars: What are the advanced rocket systems the US is sending to Ukraine?

President Biden announces latest arms shipment but stresses mid-range missiles not to be used for launching retaliatory strikes across Russian border

US president Joe Biden has announced that his country is sending Ukraine a further $700m (£560m) of military hardware, including helicopters, Javelin anti-tank weapon systems and tactical vehicles.

The shipment will also include M142 Himars, a type of multiple launch rocket system (MLRS) that represents the most powerful artillery dispatched to Volodymyr Zelensky’s resistance since the M777 Howitzers Washington provided in April.

This latest instalment of military aid represents the 11th such package approved so far by Mr Biden and is the first to draw on the $40bn (£32bn) security and economic assistance provision recently approved by Congress.

In all, the US has now given Kyiv $4.5bn (£3.6bn) in arms since Russia commenced its unprovoked and unjust invasion of its western neighbour on 24 February, the conflict now rumbling on towards its 100th day and fighting ongoing in the eastern Donbas, where Vladimir Putin’s troops have reportedly captured Sievierodonetsk.

Explaining his decision in an op-ed for The New York Times, the president said the Himars MLRS were not intended for cross-border retaliatory strikes against the enemy.

“We are not going to send to Ukraine rocket systems that can strike into Russia,” the president wrote. “That’s why I’ve decided that we will provide the Ukrainians with more advanced rocket systems and munitions that will enable them to more precisely strike key targets on the battlefield in Ukraine.”

Nevertheless, the Kremlin responded angrily on Wednesday, accusing the US of adding “fuel to the fire”, bolstering its argument that the war in Ukraine has become a proxy fight with the Nato allies despite its target not being a member of that military alliance, whose members swear to come to the defence of each other under attack.

Himars is an acronym standing for High Mobility Artillery Rocket System and is a truck-mounted MLRS used to simultaneously launch multiple GPS-guided missiles, each carrying one pod of six 227mm precision rockets.

A mid-range artillery unit typically manned by a small, trained crew in position to aim and reload, its missiles have a 50-mile range, enabling the Ukrainian military to hit Russian targets from further afield while firing from safer positions.

The M142 is a successor to the 1970s M270 model, which was capable of carrying two pods but was heavier and less agile.

Samuel Cranny-Evans, a research analyst at the Royal United Services Institute, told Al Jazeera that the new systems represent an upgrade for Ukraine, as President Zelensky has repeatedly requested, but said their effectiveness will ultimately depend on “the Ukrainian ability to conduct reconnaissance and intelligence gathering functions into Russia’s operational depth and coordinate that with the new artillery assets as they enter service”.