Ukrainian President Volodymyr Zelensky hailed the United States’ “unwavering” support after Washington announced a new $1.3 billion military aid package on Wednesday.

The aid “will help save Ukrainian lives and move closer to our common victory”, Zelensky wrote on Twitter. “We appreciate the unwavering support of the friendly American people.”

The United States announced the new $1.3 billion military aid package for Ukraine featuring air-defence systems, anti-tank missiles, drones and other equipment.

The package is part of US efforts to meet “Ukraine’s pressing requirements by committing critical near-term capabilities while also building the enduring capacity of Ukraine’s armed forces,” the US Defense Department said in a statement.

The assistance will not immediately arrive on the battlefield, as it falls under the Ukraine Security Assistance Initiative (USAI), under which Washington procures equipment from the defence industry or partners, rather than drawing it from US stocks.

The package includes four NASAMs air-defence systems and related munitions, TOW anti-tank missiles, 152 mm artillery shells, drones as well as counter-drone systems, and various vehicles.

The announcement comes as Ukrainian forces are fighting to advance against invading Russian troops in a slow-moving counteroffensive that Mykhaylo Podolyak, a senior aide to Ukraine’s president, said Wednesday “will be quite difficult, long and will take quite a lot of time”.