Asked about the nature of the new shipment to Kyiv, Spanish Foreign Minister Jose Manuel Albares, refused to give specifics.

But he insisted it was "to help Ukraine and its army defend its independence, its sovereignty and above all to protect defenceless civilians".

"If we really want to help Ukraine... the less we speak about weapons, what type and where they're coming from, the better," he told Spain's TVE public television.

Defence Minister Margarita Robles said late Thursday Spain would send a second delivery "in the coming days".

"We have already sent a first consignment and depending on how circumstances evolve, we will send another in the next few days with one aim: so Ukraine's citizens can protect and legitimately defend themselves against this terrible invasion by Russia," she told Telecinco TV channel.

Despite the reservations of his hard-left coalition ally Podemos, Socialist Prime Minister Pedro Sanchez last week said Spain would send "the Ukrainian resistance offensive military hardware".

Robles later said that the hardware, which was delivered by plane to the border between Ukraine and Poland, comprised 1,370 grenade launchers, 700,000 rounds of ammunition and an unspecified number of light machine guns.

Top EU diplomat Josep Borrell on Friday suggested that the bloc double its funding for military aid to Ukraine, raising it to 1 billion euros ($1.1 billion) to help it battle Russia's invasion.

Russia's military incursion into Ukraine, now in its third week, has seen Western countries sharply increase supplies of military aid to their pro-Western ally.

But Russia's top diplomat Sergei Lavrov has denounced the European Union and other countries for acting "dangerously" in supplying arms to Ukraine.